Records |
Author |
Zhang, Z.; Partoens, B.; Chang, K.; Peeters, F.M. |
Title |
First-principles study of transition metal impurities in Si |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
77 |
Issue |
15 |
Pages |
155201,1-8 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000255457400057 |
Publication Date |
2008-04-02 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
72 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2008 IF: 3.322 |
Call Number |
UA @ lucian @ c:irua:68846 |
Serial |
1221 |
Permanent link to this record |
|
|
|
Author |
Croitoru, M.D.; van Dyck, D.; Liu, Y.Z.; Zhang, Z. |
Title |
Measurement of specimen thickness by phase change determination in TEM |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
108 |
Issue |
12 |
Pages |
1616-1622 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
A non-destructive method for measuring the thickness of thin amorphous films composed of light elements has been developed. The method employs the statistics of the phase of the electron exit wave function. The accuracy of this method has been checked numerically by the multislice method and compared with that based on the mean inner potential. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000260808300016 |
Publication Date |
2008-06-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
2 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.843; 2008 IF: 2.629 |
Call Number |
UA @ lucian @ c:irua:75643 |
Serial |
1961 |
Permanent link to this record |
|
|
|
Author |
Wu, Z.; Zhang, Z.Z.; Chang, K.; Peeters, F.M. |
Title |
Quantum tunneling through graphene nanorings |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
Volume |
21 |
Issue |
18 |
Pages |
185201 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We investigate theoretically quantum transport through graphene nanorings in the presence of a perpendicular magnetic field. Our theoretical results demonstrate that the graphene nanorings behave like a resonant tunneling device, contrary to the Aharonov-Bohm oscillations found in conventional semiconductor rings. The resonant tunneling can be tuned by the Fermi energy, the size of the central part of the graphene nanorings and the external magnetic field. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000276672100005 |
Publication Date |
2010-04-15 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0957-4484;1361-6528; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.44 |
Times cited |
34 |
Open Access |
|
Notes |
; This work is partly supported by the NSFC, the project from the Chinese Academy of Sciences, the bilateral project between China and Sweden, the Flemish Science Foundation (FWLO-Vl) and the Belgium Science Policy (IAP). ; |
Approved |
Most recent IF: 3.44; 2010 IF: 3.652 |
Call Number |
UA @ lucian @ c:irua:95614 |
Serial |
2796 |
Permanent link to this record |
|
|
|
Author |
Zhang, Z.Z.; Wu, Z.H.; Chang, K.; Peeters, F.M. |
Title |
Resonant tunneling through S- and U-shaped graphene nanoribbons |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
Volume |
20 |
Issue |
41 |
Pages |
415203,1-415203,7 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We theoretically investigate resonant tunneling through S- and U-shaped nanostructured graphene nanoribbons. A rich structure of resonant tunneling peaks is found emanating from different quasi-bound states in the middle region. The tunneling current can be turned on and off by varying the Fermi energy. Tunability of resonant tunneling is realized by changing the width of the left and/or right leads and without the use of any external gates. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000269930100007 |
Publication Date |
2009-09-17 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0957-4484;1361-6528; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.44 |
Times cited |
32 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.44; 2009 IF: 3.137 |
Call Number |
UA @ lucian @ c:irua:79311 |
Serial |
2893 |
Permanent link to this record |
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|
|
Author |
Delville, R.; Schryvers, D.; Zhang, Z.; James, R.D. |
Title |
Transmission electron microscopy investigation of microstructures in low-hysteresis alloys with special lattice parameters |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Scripta materialia |
Abbreviated Journal |
Scripta Mater |
Volume |
60 |
Issue |
5 |
Pages |
293-296 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
A sharp drop in hysteresis is observed for shape memory alloys satisfying the compatibility condition between austenite and martensite, i.e. ë2 = 1, where ë2 is the middle eigenvalue of the transformation strain matrix. The present work investigates the evolution of microstructure by transmission electron microscopy as the composition of the Ti50Ni50−xPdx system is systemically tuned to achieve the condition ë2 = 1. Changes in morphology, twinning density and twinning modes are reported along with twinless martensite and exact austenitemartensite interfaces. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
Language |
|
Wos |
000262553300007 |
Publication Date |
2008-11-08 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1359-6462; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.747 |
Times cited |
56 |
Open Access |
|
Notes |
Multimat |
Approved |
Most recent IF: 3.747; 2009 IF: 2.949 |
Call Number |
UA @ lucian @ c:irua:76017 |
Serial |
3710 |
Permanent link to this record |
|
|
|
Author |
Zhang, Z.; Ma, L.N.; Liao, X.Z.; van Landuyt, J. |
Title |
A transmission electron-microscopy study of crystalline surface domains on al-co decagonal quasi-crystals and the \tau2-Al13CO4 approximant |
Type |
A1 Journal article |
Year |
1994 |
Publication |
Philosophical magazine letters |
Abbreviated Journal |
Phil Mag Lett |
Volume |
70 |
Issue |
5 |
Pages |
303-310 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Twin-domains of a b.c.c. crystalline phase with a = 0.29 nm have been found in a surface layer on surfaces of Al-Co decagonal quasicrystals and the coexisting tau(2)-Al13Co4 crystalline approximant. These surface layer domains are introduced during the preparation of electron microscopy thin films by ion milling. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
A1994PQ20900008 |
Publication Date |
2007-07-08 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0950-0839;1362-3036; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.087 |
Times cited |
4 |
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ lucian @ c:irua:99816 |
Serial |
3715 |
Permanent link to this record |
|
|
|
Author |
Delville, R.; Kasinathan, S.; Zhang, Z.; van Humbeeck, J.; James, R.D.; Schryvers, D. |
Title |
Transmission electron microscopy study of phase compatibility in low hysteresis shape memory alloys |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Philosophical magazine |
Abbreviated Journal |
Philos Mag |
Volume |
90 |
Issue |
1/4 |
Pages |
177-195 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Recent findings have linked low hysteresis in shape memory alloys with phase compatibility between austenite and martensite. To investigate the evolution of microstructure as phase compatibility increases and hysteresis is reduced, transmission electron microscopy was used to study the alloy system Ti50Ni50xPdx, where the composition is systemically tuned to approach perfect compatibility. Changes in morphology, twinning density and twinning modes are reported, along with special microstructures occurring when compatibility is achieved. In addition, the interface between austenite and a single variant of martensite was studied by high-resolution and conventional electron microscopy. The low energy configuration of the interface detailed in this article suggests that it plays an important role in the lowering of hysteresis compared to classical habit plane interfaces. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000274576500013 |
Publication Date |
2010-01-16 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1478-6435;1478-6443; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.505 |
Times cited |
70 |
Open Access |
|
Notes |
Multimat; FWO |
Approved |
Most recent IF: 1.505; 2010 IF: 1.304 |
Call Number |
UA @ lucian @ c:irua:79859 |
Serial |
3718 |
Permanent link to this record |
|
|
|
Author |
Zhang, Z.; Geng, W.; van Landuyt, J.; Van Tendeloo, G. |
Title |
A transmission electron microscopy study of tweed-like structures in Al62Cu17.5CO17.5Si3 decagonal quasicrystals |
Type |
A1 Journal article |
Year |
1995 |
Publication |
Philosophical magazine: A: physics of condensed matter: defects and mechanical properties |
Abbreviated Journal |
|
Volume |
71 |
Issue |
5 |
Pages |
1177-1189 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
|
Language |
|
Wos |
A1995QW79500016 |
Publication Date |
0000-00-00 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0141-8610; 1364-2804 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
7 |
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ lucian @ c:irua:13296 |
Serial |
3721 |
Permanent link to this record |
|
|
|
Author |
Zhang, Z.Z.; Peeters, F.M. |
Title |
Tuning of energy levels and optical properties of graphene quantum dots |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
77 |
Issue |
|
Pages |
235411,1-5 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000257289500101 |
Publication Date |
2008-06-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
228 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2008 IF: 3.322 |
Call Number |
UA @ lucian @ c:irua:69638 |
Serial |
3750 |
Permanent link to this record |
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|
|
Author |
Ren, Z.; Wu, M.; Chen, X.; Li, W.; Li, M.; Wang, F.; Tian, H.; Chen, J.; Xie, Y.; Mai, J.; Li, X.; Lu, X.; Lu, Y.; Zhang, H.; Van Tendeloo, G.; Zhang, Z.; Han, G. |
Title |
Electrostatic force-driven oxide heteroepitaxy for interface control |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
Volume |
30 |
Issue |
38 |
Pages |
1707017 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Oxide heterostructure interfaces create a platform to induce intriguing electric and magnetic functionalities for possible future devices. A general approach to control growth and interface structure of oxide heterostructures will offer a great opportunity for understanding and manipulating the functionalities. Here, it is reported that an electrostatic force, originating from a polar ferroelectric surface, can be used to drive oxide heteroepitaxy, giving rise to an atomically sharp and coherent interface by using a low-temperature solution method. These heterostructures adopt a fascinating selective growth, and show a saturation thickness and the reconstructed interface with concentrated charges accumulation. The ferroelectric polarization screening, developing from a solid-liquid interface to the heterostructure interface, is decisive for the specific growth. At the interface, a charge transfer and accumulation take place for electrical compensation. The facile approach presented here can be extremely useful for controlling oxide heteroepitaxy and producing intriguing interface functionality via electrostatic engineering. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000444671900002 |
Publication Date |
2018-08-07 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0935-9648 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
19.791 |
Times cited |
4 |
Open Access |
Not_Open_Access |
Notes |
; Z.H.R., M.J.W., and X.C. contributed equally to this work. This work was financially supported by the National Natural Science Foundation of China (Grant Nos. 51232006, 51472218, 11474249, 61574123, 11374009, and 11234011), the National 973 Program of China (Grant No. 2015CB654901), National Young 1000 Talents Program of China, the Fundamental Research Funds for the Central Universities (Grant No. 2017FZA4008), and the 111 Project under Grant No. B16042. J.M. and X.L. gratefully thank the beam time and technical supports provided by 23A SWAXS beamline at NSRRC, Hsinchu. ; |
Approved |
Most recent IF: 19.791 |
Call Number |
UA @ lucian @ c:irua:153628 |
Serial |
5098 |
Permanent link to this record |
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|
|
Author |
Li, W.; Hu, Z.-Y.; Zhang, Z.; Wei, P.; Zhang, J.; Pu, Z.; Zhu, J.; He, D.; Mu, S.; Van Tendeloo, G. |
Title |
Nano-single crystal coalesced PtCu nanospheres as robust bifunctional catalyst for hydrogen evolution and oxygen reduction reactions |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Journal of catalysis |
Abbreviated Journal |
J Catal |
Volume |
375 |
Issue |
375 |
Pages |
164-170 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Because of high electrocatalytic activity, Pt based metal nanospheres (NSs) have attracted a lot of attention. Hence, multi-particle nano-single crystal coalesced PtCu NSs are designed and successfully synthesized by a cost-effective aqueous solution method. The formed PtCu NS catalyst exhibits a superior hydrogen evolution reaction (HER) electrocatalytic activity with an ultralow onset potential of 18 mV at the current density of 2 mA/cm(2) and high mass activity of 1.08 A/mg(pt) (7.2 times higher than that of commercial Pt/C catalysts). Also, it shows an enhancement of 3.2 and 2.7 times in the mass and specific activities toward oxygen reduction reaction (ORR) compared to that of Pt/C. Moreover, it possesses an excellent catalytic durability for both ORR and HER. Even after 10,000 cycles, its ORR mass activity retains 87% of its initial value. The density functional theory (DFT) calculations demonstrate that by introducing Cu atoms into the Pt lattice, a downshift of the D-band center and favorable hydrogen adsorption free energy of approaching to zero (Delta G) occur, indicating the increased electrocatalytic activity of Pt electrocatalysts. (C) 2019 Elsevier Inc. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000486104500017 |
Publication Date |
2019-06-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-9517 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.844 |
Times cited |
25 |
Open Access |
|
Notes |
; Z-Y. Hu thank for the support of “the Fundamental Research Funds for the Central Universities (WUT: 2017111055, 2018111039GX, 2018IVA095)”. S. Mu and J. Zhang acknowledges the support from the National Natural Science Foundation of China (NSFC) through award Nos. 51672204 and 21875221 and the opening funds of State Key Laboratory of Advanced Technology for Materials Synthesis and Processing (2019-KF-13), Wuhan University of Technology. ; |
Approved |
Most recent IF: 6.844 |
Call Number |
UA @ admin @ c:irua:162903 |
Serial |
5391 |
Permanent link to this record |
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|
|
Author |
Zhang, Z.; Rosalie, J.M.; Medhekar, N.V.; Bourgeois, L. |
Title |
Resolving the FCC/HCP interfaces of the \gamma'(Ag2Al) precipitate phase in aluminium |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
174 |
Issue |
174 |
Pages |
116-130 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The gamma'(Ag2Al) phase in the Al-Ag alloy system has served as a textbook example for understanding phase transformations, precipitating hexagonal close-packed (HCP) crystals in the face-centred cubic (FCC) aluminium matrix. The gamma' precipitates display fully coherent interfaces at their broad facets and semicoherent interfaces at their edges. Shockley partial dislocations are expected to decorate the semicoherent interface due to the FCC-HCP structural transformation. Determining the exact locations and core structures of interfacial dislocations, however, remains challenging. In this study, we used aberration-corrected scanning transmission electron microscopy and atomistic simulations to re-visit this classical system. We characterised and explained the Ag segregation at coherent interfaces in the early stage of precipitation. For semicoherent interfaces, interfacial dislocations and reconstructions were revealed by bridging advanced microstructure characterisation and atomistic simulations. In particular, we discovered a new FCC/HCP interfacial structure that displays a unique combination of Shockley partial, Lomer-Cottrell and Hirth dislocations that evolve from the known interfacial structure purely composed by Shockley partial dislocations. Our findings show that the FCC-HCP transformation is more complex than hitherto considered, due to the interplay between structure and composition confined at interfaces. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
|
Language |
|
Wos |
000474501300011 |
Publication Date |
2019-05-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.301 |
Times cited |
3 |
Open Access |
|
Notes |
; The authors acknowledge funding from the Australian Research Council (LE0454166, LE110100223), the Victorian State Government and Monash University for instrumentation, and use of the facilities within the Monash Centre for Electron Microscopy. LB and NM acknowledge the financial support of the Australian Research Council (DP150100558). The authors also gratefully acknowledge the computational support from Monash Advanced Research Computing Hybrid, the National Computational Infrastructure and Pawsey Supercomputing Centre. ZZ is thankful to Monash University for a Monash Graduate Scholarship, a Monash International Postgraduate Research Scholarship and a Monash Centre for Electron Microscopy Postgraduate Scholarship. ZZ is indebted to Matthew Weyland for his training in aberration-corrected electron microscopy, Scott Findlay for his help on image simulations, Xiang Gao for alloy casting and Ian Polmear for discussions. ; |
Approved |
Most recent IF: 5.301 |
Call Number |
UA @ admin @ c:irua:161192 |
Serial |
5395 |
Permanent link to this record |
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|
|
Author |
Weng, Y.; Ding, L.; Zhang, Z.; Jia, Z.; Wen, B.; Liu, Y.; Muraishi, S.; Li, Y.; Liu, Q. |
Title |
Effect of Ag addition on the precipitation evolution and interfacial segregation for Al-Mg-Si alloy |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
180 |
Issue |
180 |
Pages |
301-316 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The effect of Ag addition on the precipitation evolution and interfacial segregation for Al-Mg-Si alloys was systematically investigated by atomic resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), atom probe tomography (APT) and density functional theory (DFT) calculation. At the early aging stage, Ag atoms could enter clusters and refine the distribution of these clusters. Then, Ag atoms preferentially segregate at the GP zone/alpha-Al and beta ''/alpha-Al interfaces at the peak aging stage by the replacement of Al atoms in FCC matrix. With prolonging aging time, Ag atoms generally incorporate into the interior of beta '' precipitate, facilitating the formation of QP lattice (a hexagonal network of Si atomic columns) and the local symmetry substructures, Ag sub-unit (1) and Ag sub-unit (2). At the over-aged stage, the Ag sub-unit (1) and Ag sub-unit (2) could transform to the beta'(Ag) (i.e. beta'(Ag1) and beta'(Ag2).) and Q'(Ag) unit cells, respectively. All the precipitates at the over-aging stage have a composite and disordered structure due to the coexistence of different unit cells (beta'(Ag1), beta'(Ag2), Q'(Ag) and beta') and the non-periodic arrangement of Ag atoms within the precipitate. In the equilibrium stage, the incorporated Ag atoms in the precipitates release into the alpha-Al matrix as solute atoms or form Ag particles. In general, Ag atoms undergo a process of “segregate at the precipitate/matrix interface -> incorporate into the interior of precipitate -> release into the alpha-Al matrix” during the precipitation for Al-Mg-Si-Ag alloys. Besides, Ag segregation is found at the interfaces of almost all metastable phases (including GP zone, beta '', beta'/beta'(Ag) phase) in Al-Mg-Si-Ag alloys. The Ag segregation at the beta'/alpha-Al interface could increase the length/diameter ratio of beta' phase and thus promote the additional strengthening potential of these alloys. These findings provide a new route for precipitation hardening by promoting the nucleation and morphology evolution of precipitates. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
|
Wos |
000495519100028 |
Publication Date |
2019-09-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.301 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 5.301 |
Call Number |
UA @ admin @ c:irua:164641 |
Serial |
6295 |
Permanent link to this record |
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|
Author |
Du, K.; Zhang, M.; Dai, C.; Zhou, Z.N.; Xie, Y.W.; Ren, Z.H.; Tian, H.; Chen, L.Q.; Van Tendeloo, G.; Zhang, Z. |
Title |
Manipulating topological transformations of polar structures through real-time observation of the dynamic polarization evolution |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
10 |
Issue |
10 |
Pages |
4864 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Topological structures based on controllable ferroelectric or ferromagnetic domain configurations offer the opportunity to develop microelectronic devices such as high-density memories. Despite the increasing experimental and theoretical insights into various domain structures (such as polar spirals, polar wave, polar vortex) over the past decade, manipulating the topological transformations of polar structures and comprehensively understanding its underlying mechanism remains lacking. By conducting an in-situ non-contact bias technique, here we systematically investigate the real-time topological transformations of polar structures in PbTiO3/SrTiO3 multilayers at an atomic level. The procedure of vortex pair splitting and the transformation from polar vortex to polar wave and out-of-plane polarization are observed step by step. Furthermore, the redistribution of charge in various topological structures has been demonstrated under an external bias. This provides new insights for the symbiosis of polar and charge and offers an opportunity for a new generation of microelectronic devices. |
Address |
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Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000492835100002 |
Publication Date |
2019-10-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 12.124 |
Call Number |
UA @ admin @ c:irua:164681 |
Serial |
6307 |
Permanent link to this record |
|
|
|
Author |
Du, K.; Guo, L.; Peng, J.; Chen, X.; Zhou, Z.-N.; Zhang, Y.; Zheng, T.; Liang, Y.-P.; Lu, J.-P.; Ni, Z.-H.; Wang, S.-S.; Van Tendeloo, G.; Zhang, Z.; Dong, S.; Tian, H. |
Title |
Direct visualization of irreducible ferrielectricity in crystals |
Type |
A1 Journal article |
Year |
2020 |
Publication |
npj Quantum Materials |
Abbreviated Journal |
|
Volume |
5 |
Issue |
1 |
Pages |
49-7 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
In solids, charge polarity can one-to-one correspond to spin polarity phenomenologically, e.g., ferroelectricity/ferromagnetism, antiferroelectricity/antiferromagnetism, and even dipole-vortex/magnetic-vortex, but ferrielectricity/ferrimagnetism kept telling a disparate story in microscopic level. Since the definition of a charge dipole involves more than one ion, there may be multiple choices for a dipole unit, which makes most ferrielectric orders equivalent to ferroelectric ones, i.e., this ferrielectricity is not necessary to be a real independent branch of polarity. In this work, by using the spherical aberration-corrected scanning transmission electron microscope, we visualize a nontrivial ferrielectric structural evolution in BaFe2Se3, in which the development of two polar sub-lattices is out-of-sync, for which we term it as irreducible ferrielectricity. Such irreducible ferrielectricity leads to a non-monotonic behavior for the temperature-dependent polarization, and even a compensation point in the ordered state. Our finding unambiguously distinguishes ferrielectrics from ferroelectrics in solids. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000551499400001 |
Publication Date |
2020-07-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2397-4648 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
|
Open Access |
OpenAccess |
Notes |
; We acknowledge the National Natural Science Foundation of China (Grant Nos. 11834002, 11674055, and 11234011), National Key R&D Program of China 2017YFB0703100, and the 111 Project (Grant No. B16042). K.D. acknowledges the China Scholarship Council (CSC, No.201806320230) for sponsorship and 2019 Zhejiang University Academic Award for Outstanding Doctoral Candidates. We thank Prof. Fang Lin for providing guidance on calculating atoms position and Dr. Andrew Studer for performing neutron powder diffraction. We thank Prof. Sang-Wook Cheong, Prof. Zhigao Sheng, Prof. Qianghua Wang, Prof. Meng Wang, Prof. Renkui Zheng, Prof. Takuya Aoyama, Dr. Zhibo Yan, and Dr. Meifeng Liu for valuable discussion and/or technical help during measurements. ; |
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:171225 |
Serial |
6486 |
Permanent link to this record |
|
|
|
Author |
Bourgeois, L.; Zhang, Y.; Zhang, Z.; Chen, Y.; Medhekar, N., V |
Title |
Transforming solid-state precipitates via excess vacancies |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat Commun |
Volume |
11 |
Issue |
1 |
Pages |
1248 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Many phase transformations associated with solid-state precipitation look structurally simple, yet, inexplicably, take place with great difficulty. A classic case of difficult phase transformations is the nucleation of strengthening precipitates in high-strength lightweight aluminium alloys. Here, using a combination of atomic-scale imaging, simulations and classical nucleation theory calculations, we investigate the nucleation of the strengthening phase theta' onto a template structure in the aluminium-copper alloy system. We show that this transformation can be promoted in samples exhibiting at least one nanoscale dimension, with extremely high nucleation rates for the strengthening phase as well as for an unexpected phase. This template-directed solid-state nucleation pathway is enabled by the large influx of surface vacancies that results from heating a nanoscale solid. Template-directed nucleation is replicated in a bulk alloy as well as under electron irradiation, implying that this difficult transformation can be facilitated under the general condition of sustained excess vacancy concentrations. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000549162600025 |
Publication Date |
2020-03-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
16.6 |
Times cited |
5 |
Open Access |
OpenAccess |
Notes |
; The authors are indebted to Matthew Weyland for his expert advice on aberrationcorrected scanning transmission electron microscopy. L.B. would like to acknowledge initial discussions with B.C. Muddle and J.F. Nie many years ago regarding the possible thermodynamic role of vacancies in solid-state precipitation. The authors acknowledge funding from the Australian Research Council (LE0454166, LE110100223), the Victorian State Government and Monash University for instrumentation, and use of the facilities within the Monash Centre for Electron Microscopy. The authors thank Flame Burgmann, Dougal McCulloch and Edwin Mayes for access to and assistance at the Microscopy and Microanalysis Facility at RMIT University. L.B. and N.M. acknowledge the financial support of the Australian Research Council (DP150100558). Authors also gratefully acknowledge the computational support from MonARCH, MASSIVE and the National Computing Infrastructure and Pawsey Supercomputing Centre. ZZ and YZ are thankful to Monash University for a Monash Graduate Scholarship, a Monash International Postgraduate Research Scholarship. Z.Z. is grateful for a Monash Centre for Electron Microscopy Postgraduate Scholarship. The authors are grateful to Anita Hill for advice. ; |
Approved |
Most recent IF: 16.6; 2020 IF: 12.124 |
Call Number |
UA @ admin @ c:irua:170797 |
Serial |
6635 |
Permanent link to this record |
|
|
|
Author |
Ding, L.; Zhao, M.; Ehlers, F.J.H.; Jia, Z.; Zhang, Z.; Weng, Y.; Schryvers, D.; Liu, Q.; Idrissi, H. |
Title |
“Branched” structural transformation of the L12-Al3Zr phase manipulated by Cu substitution/segregation in the Al-Cu-Zr alloy system |
Type |
A1 Journal article |
Year |
2024 |
Publication |
Journal of materials science & technology |
Abbreviated Journal |
Journal of Materials Science & Technology |
Volume |
185 |
Issue |
|
Pages |
186-206 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The effect of Cu on the evolution of the Al3Zr phase in an Al-Cu-Zr cast alloy during solution treatment at 500 °C has been thoroughly studied by combining atomic resolution high-angle annular dark-field scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy and first-principles cal- culations. The heat treatment initially produces a pure L12-Al3Zr microstructure, allowing for about 13 % Cu to be incorporated in the dispersoid. Cu incorporation increases the energy barrier for anti-phase boundary (APB) activation, thus stabilizing the L12 structure. Additional heating leads to a Cu-induced “branched”path for the L12 structural transformation, with the latter process accelerated once the first APB has been created. Cu atoms may either (i) be repelled by the APBs, promoting the transformation to a Cu-poor D023 phase, or (ii) they may segregate at one Al-Zr layer adjacent to the APB, promoting a transformation to a new thermodynamically favored phase, Al4CuZr, formed when these segregation layers are periodically arranged. Theoretical studies suggest that the branching of the L12 transformation path is linked to the speed at which an APB is created, with Cu attraction triggered by a comparatively slow process. This unexpected transformation behavior of the L12-Al3Zr phase opens a new path to understanding, and potentially regulating the Al3Zr dispersoid evolution for high temperature applications. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
001154261100001 |
Publication Date |
2023-12-24 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1005-0302 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
10.9 |
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
This work was supported by the National Key Research and Development Program (No. 2020YFA0405900), the National Natural Science Foundation of China (Grant No. 52371111 and U2141215 ), the Natural Science Foundation of Jiangsu Province (No. BE2022159 ). We are grateful to the High Performance Computing Center of Nanjing Tech University for supporting the computational resources. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR- FNRS). |
Approved |
Most recent IF: 10.9; 2024 IF: 2.764 |
Call Number |
EMAT @ emat @c:irua:202392 |
Serial |
8981 |
Permanent link to this record |
|
|
|
Author |
De Backer, A.; Zhang, Z.; van den Bos, K.H.W.; Bladt, E.; Sánchez‐Iglesias, A.; Liz‐Marzán, L.M.; Nellist, P.D.; Bals, S.; Van Aert, S. |
Title |
Element Specific Atom Counting at the Atomic Scale by Combining High Angle Annular Dark Field Scanning Transmission Electron Microscopy and Energy Dispersive X‐ray Spectroscopy |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Small methods |
Abbreviated Journal |
Small Methods |
Volume |
|
Issue |
|
Pages |
2200875 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
A new methodology is presented to count the number of atoms in multimetallic nanocrystals by combining energy dispersive X-ray spectroscopy (EDX) and high angle annular dark field scanning transmission electron microscopy (HAADF STEM). For this purpose, the existence of a linear relationship between the incoherent HAADF STEM and EDX images is exploited. Next to the number of atoms for each element in the atomic columns, the method also allows quantification of the error in the obtained number of atoms, which is of importance given the noisy nature of the acquired EDX signals. Using experimental images of an Au@Ag core–shell nanorod, it is demonstrated that 3D structural information can be extracted at the atomic scale. Furthermore, simulated data of an Au@Pt core–shell nanorod show the prospect to characterize heterogeneous nanostructures with adjacent atomic numbers. |
Address |
|
Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000862072700001 |
Publication Date |
2022-09-30 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2366-9608 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.4 |
Times cited |
5 |
Open Access |
OpenAccess |
Notes |
This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S.V.A., Grant 815128 REALNANO to S.B., and Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0267.18N, G.0502.18N, G.0346.21N) and a postdoctoral grant to A.D.B.; esteem3reported; esteem3JRA |
Approved |
Most recent IF: 12.4 |
Call Number |
EMAT @ emat @c:irua:191570 |
Serial |
7109 |
Permanent link to this record |
|
|
|
Author |
Zhang, Z.; Lobato, I.; De Backer, A.; Van Aert, S.; Nellist, P. |
Title |
Fast generation of calculated ADF-EDX scattering cross-sections under channelling conditions |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
|
Volume |
246 |
Issue |
|
Pages |
113671 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Advanced materials often consist of multiple elements which are arranged in a complicated structure. Quantitative scanning transmission electron microscopy is useful to determine the composition and thickness of nanostructures at the atomic scale. However, significant difficulties remain to quantify mixed columns by comparing the resulting atomic resolution images and spectroscopy data with multislice simulations where dynamic scattering needs to be taken into account. The combination of the computationally intensive nature of these simulations and the enormous amount of possible mixed column configurations for a given composition indeed severely hamper the quantification process. To overcome these challenges, we here report the development of an incoherent non-linear method for the fast prediction of ADF-EDX scattering cross-sections of mixed columns under channelling conditions. We first explain the origin of the ADF and EDX incoherence from scattering physics suggesting a linear dependence between those two signals in the case of a high-angle ADF detector. Taking EDX as a perfect incoherent reference mode, we quantitatively examine the ADF longitudinal incoherence under different microscope conditions using multislice simulations. Based on incoherent imaging, the atomic lensing model previously developed for ADF is now expanded to EDX, which yields ADF-EDX scattering cross-section predictions in good agreement with multislice simulations for mixed columns in a core–shell nanoparticle and a high entropy alloy. The fast and accurate prediction of ADF-EDX scattering cross-sections opens up new opportunities to explore the wide range of ordering possibilities of heterogeneous materials with multiple elements. |
Address |
|
Corporate Author |
Zezhong Zhang |
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000995063900001 |
Publication Date |
2022-12-28 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.2 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
European Research Council 770887 PICOMETRICS; Fonds Wetenschappelijk Onderzoek No.G.0502.18N; Horizon 2020, 770887 ; Horizon 2020 Framework Programme; European Research Council, 823717 ESTEEM3 ; esteem3reported; esteem3JRa |
Approved |
Most recent IF: 2.2; 2023 IF: 2.843 |
Call Number |
EMAT @ emat @c:irua:195890 |
Serial |
7251 |
Permanent link to this record |
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|
|
Author |
Zhang, Z.; Chen, X.; Shi, X.; Hu, Y.; Huang, J.; Liu, S.; Ren, Z.; Huang, H.; Han, G.; Van Tendeloo, G.; Tian, H. |
Title |
Morphotropic phase boundary in pure perovskite lead titanate at room temperature |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Materials Today Nano |
Abbreviated Journal |
|
Volume |
20 |
Issue |
|
Pages |
100275-5 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
For many decades, great efforts have been devoted to pursue a large piezoelectric response by an intelligent design of morphotropic phase boundaries (MPB) in solid solutions, where tetragonal (T) and rhombohedral (R) structures coexist. For example, classical PbZrxTi1-xO3 and Pb(Mg1/3Nb2/3)O-3-PbTiO3 single crystals demonstrate a giant piezoelectric response near MPB. However, as the end member of these solids, perovskite-structured PbTiO3 always adopts the T phase at room temperature. Here, we report a pathway to create room temperature MPB in a single-phase PbTiO3. The uniaxial stress along the c-axis drives a T-R phase transition bridged by a monoclinic (M) phase, which facilitates a polarization rotation in the monodomain PbTiO3. Meanwhile, we demonstrate that the coexistence of T and R phases at room temperature can be achieved via an extremely mismatched heterointerface system. The uniaxial pressure is proved as an efficient way to break the inherent symmetry and able to substantially tailor the phase transition temperature Tc. These findings provide new insights into MPB, offering the opportunity to explore the giant piezoelectric response in single-phase materials. (c) 2022 Elsevier Ltd. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
|
Wos |
000906548600002 |
Publication Date |
2022-10-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2588-8420 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
10.3 |
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
|
Approved |
Most recent IF: 10.3 |
Call Number |
UA @ admin @ c:irua:193477 |
Serial |
7324 |
Permanent link to this record |
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|
Author |
Zhang, H.; Jin, Q.; Hu, T.; Liu, X.; Zhang, Z.; Hu, C.; Zhou, Y.; Han, Y.; Wang, X. |
Title |
Electron-irradiation-facilitated production of chemically homogenized nanotwins in nanolaminated carbides |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Journal of Advanced Ceramics |
Abbreviated Journal |
|
Volume |
12 |
Issue |
6 |
Pages |
1288-1297 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Twin boundaries have been exploited to stabilize ultrafine grains and improve mechanical properties of nanomaterials. The production of the twin boundaries and nanotwins is however prohibitively challenging in carbide ceramics. Using a scanning transmission electron microscope as a unique platform for atomic-scale structure engineering, we demonstrate that twin platelets could be produced in carbides by engineering antisite defects. The antisite defects at metal sites in various layered ternary carbides are collectively and controllably generated, and the metal elements are homogenized by electron irradiation, which transforms a twin-like lamellae into nanotwin platelets. Accompanying chemical homogenization, alpha-Ti3AlC2 transforms to unconventional beta-Ti3AlC2. The chemical homogeneity and the width of the twin platelets can be tuned by dose and energy of bombarding electrons. Chemically homogenized nanotwins can boost hardness by similar to 45%. Our results provide a new way to produce ultrathin (< 5 nm) nanotwin platelets in scientifically and technologically important carbide materials and showcase feasibility of defect engineering by an angstrom-sized electron probe. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001004930200012 |
Publication Date |
2023-04-19 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2226-4108; 2227-8508 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
16.9 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 16.9; 2023 IF: 1.198 |
Call Number |
UA @ admin @ c:irua:197470 |
Serial |
8860 |
Permanent link to this record |
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Author |
Soltan, S.; Macke, S.; Ilse, S.E.; Pennycook, T.; Zhang, Z.L.; Christiani, G.; Benckiser, E.; Schuetz, G.; Goering, E. |
Title |
Ferromagnetic order controlled by the magnetic interface of LaNiO3/La2/3Ca1/3MnO3 superlattices |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Scientific reports |
Abbreviated Journal |
|
Volume |
13 |
Issue |
1 |
Pages |
1-9 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Interface engineering in complex oxide superlattices is a growing field, enabling manipulation of the exceptional properties of these materials, and also providing access to new phases and emergent physical phenomena. Here we demonstrate how interfacial interactions can induce a complex charge and spin structure in a bulk paramagnetic material. We investigate a superlattice (SLs) consisting of paramagnetic LaNiO3 (LNO) and highly spin-polarized ferromagnetic La2/3Ca1/3MnO3 (LCMO), grown on SrTiO3 (001) substrate. We observed emerging magnetism in LNO through an exchange bias mechanism at the interfaces in X-ray resonant magnetic reflectivity. We find non-symmetric interface induced magnetization profiles in LNO and LCMO which we relate to a periodic complex charge and spin superstructure. High resolution scanning transmission electron microscopy images reveal that the upper and lower interfaces exhibit no significant structural variations. The different long range magnetic order emerging in LNO layers demonstrates the enormous potential of interfacial reconstruction as a tool for tailored electronic properties. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000985158100013 |
Publication Date |
2023-03-26 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.6 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 4.6; 2023 IF: 4.259 |
Call Number |
UA @ admin @ c:irua:197426 |
Serial |
8867 |
Permanent link to this record |
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Author |
Zhang, Z.; Lobato, I.; Brown, H.; Jannis, D.; Verbeeck, J.; Van Aert, S.; Nellist, P. |
Title |
Generalised oscillator strength for core-shell electron excitation by fast electrons based on Dirac solutions |
Type |
Dataset |
Year |
2023 |
Publication |
|
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
|
Keywords |
Dataset; Electron microscopy for materials research (EMAT) |
Abstract |
Inelastic excitation as exploited in Electron Energy Loss Spectroscopy (EELS) contains a rich source of information that is revealed in the scattering process. To accurately quantify core-loss EELS, it is common practice to fit the observed spectrum with scattering cross-sections calculated using experimental parameters and a Generalized Oscillator Strength (GOS) database [1]. The GOS is computed using Fermi’s Golden Rule and orbitals of bound and excited states. Previously, the GOS was based on Hartree-Fock solutions [2], but more recently Density Functional Theory (DFT) has been used [3]. In this work, we have chosen to use the Dirac equation to incorporate relativistic effects and have performed calculations using Flexible Atomic Code (FAC) [4]. This repository contains a tabulated GOS database based on Dirac solutions for computing double differential cross-sections under experimental conditions. We hope the Dirac-based GOS database can benefit the EELS community for both academic use and industry integration. Database Details: – Covers all elements (Z: 1-108) and all edges – Large energy range: 0.01 – 4000 eV – Large momentum range: 0.05 -50 Å-1 – Fine log sampling: 128 points for energy and 256 points for momentum – Data format: GOSH [3] Calculation Details: – Single atoms only; solid-state effects are not considered – Unoccupied states before continuum states of ionization are not considered; no fine structure – Plane Wave Born Approximation – Frozen Core Approximation is employed; electrostatic potential remains unchanged for orthogonal states when – core-shell electron is excited – Self-consistent Dirac–Fock–Slater iteration is used for Dirac calculations; Local Density Approximation is assumed for electron exchange interactions; continuum states are normalized against asymptotic form at large distances – Both large and small component contributions of Dirac solutions are included in GOS – Final state contributions are included until the contribution of the previous three states falls below 0.1%. A convergence log is provided for reference. Version 1.1 release note: – Update to be consistent with GOSH data format [3], all the edges are now within a single hdf5 file. A notable change in particular, the sampling in momentum is in 1/m, instead of previously in 1/Å. Great thanks to Gulio Guzzinati for his suggestions and sending conversion script. Version 1.2 release note: – Add “File Type / File version” information [1] Verbeeck, J., and S. Van Aert. Ultramicroscopy 101.2-4 (2004): 207-224. [2] Leapman, R. D., P. Rez, and D. F. Mayers. The Journal of Chemical Physics 72.2 (1980): 1232-1243. [3] Segger, L, Guzzinati, G, & Kohl, H. Zenodo (2023). doi:10.5281/zenodo.7645765 [4] Gu, M. F. Canadian Journal of Physics 86(5) (2008): 675-689. |
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Wos |
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Publication Date |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
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ISBN |
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Additional Links |
UA library record |
Impact Factor |
|
Times cited |
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Open Access |
Not_Open_Access |
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:203392 |
Serial |
9042 |
Permanent link to this record |
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Author |
Xiao, H.; Zhang, Z.; Xu, W.; Wang, Q.; Xiao, Y.; Ding, L.; Huang, J.; Li, H.; He, B.; Peeters, F.M. |
Title |
Terahertz optoelectronic properties of synthetic single crystal diamond |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Diamond and related materials |
Abbreviated Journal |
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Volume |
139 |
Issue |
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Pages |
110266-110268 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
A systematic investigation is undertaken for studying the optoelectronic properties of single crystal diamond (SCD) grown by microwave plasma chemical vapor deposition (MPCVD). It is indicated that, without intentional doping and surface treatment during the sample growth, the terahertz (THz) optical conduction in SCD is mainly affected by surface H-terminations, -OH-, O- and N-based functional groups. By using THz time-domain spectroscopy (TDS), we measure the transmittance, the complex dielectric constant and optical conductivity σ(ω) of SCD. We find that SCD does not show typical semiconductor characteristics in THz regime, where σ(ω) cannot be described rightly by the conventional Drude formula. Via fitting the real and imaginary parts of σ(ω) to the Drude-Smith formula, the ratio of the average carrier density to the effective electron mass γ = ne/m*, the electronic relaxation time τ and the electronic backscattering or localization factor can be determined optically. The temperature dependence of these parameters is examined. From the temperature dependence of γ, a metallic to semiconductor transition is observed at about T = 10 K. The temperature dependence of τ is mainly induced by electron coupling with acoustic-phonons and there is a significant effect of photon-induced electron backscattering or localization in SCD. This work demonstrates that THz TDS is a powerful technique in studying SCD which contains H-, N- and O-based bonds and has low electron density and high dc resistivity. The results obtained from this study can benefit us to gain an in-depth understanding of SCD and may provide new guidance for the application of SCD as electronic, optical and optoelectronic materials. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
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Publication Date |
2023-08-02 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0925-9635 |
ISBN |
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Additional Links |
UA library record |
Impact Factor |
4.1 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 4.1; 2023 IF: 2.561 |
Call Number |
UA @ admin @ c:irua:200920 |
Serial |
9103 |
Permanent link to this record |
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Author |
Zhang, Z.; Bourgeois, L.; Zhang, Y.; Rosalie, J.M.; Medhekar, N. |
Title |
Advanced imaging and simulations of precipitate interfaces in aluminium alloys and their role in phase transformations |
Type |
P1 Proceeding |
Year |
2020 |
Publication |
MATEC web of conferences
T2 – 17th International Conference on Aluminium Alloys (ICAA), October 26-29, 2020 |
Abbreviated Journal |
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Volume |
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Issue |
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Pages |
09003 |
Keywords |
P1 Proceeding; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Precipitation is accompanied by the formation and migration of heterophase interfaces. Using the combined approach of advanced imaging and atomistic simulations, we studied the precipitate-matrix interfaces in various aluminium alloy systems, aiming to resolve their detailed atomic structures and illuminate their role in phase transformations. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000652552200053 |
Publication Date |
2020-11-05 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
326 |
Series Issue |
|
Edition |
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ISSN |
2261-236x; 2274-7214 |
ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:179147 |
Serial |
6851 |
Permanent link to this record |