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Author | Massobrio, C.; Djimbi, D.M.; Matsubara, M.; Scipioni, R.; Boero, M. | ||||
Title | Stability of Ge12C48 and Ge20C40 heterofullerenes : a first principles molecular dynamics study | Type | A1 Journal article | ||
Year | 2013 | Publication | Chemical physics letters | Abbreviated Journal | Chem Phys Lett |
Volume | 556 | Issue | Pages | 163-167 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | By using first-principles molecular dynamics, we address the issue of structural stability for the C-60 Ge-m(m) family of doped heterofullerenes through a set of calculations targeting C48Ge12 and C40Ge20. Three kinds of theoretical tools are employed: (a) static structural optimization, (b) a bonding analysis based on localized orbitals (Wannier wavefunctions and centers) and (c) first-principles molecular dynamics at finite temperature. This latter tool allows concluding that the segregated form of C40Ge20 is less stable than its Si-based counterpart. However, the non-segregated forms of C40Ge20 and C40Si20 have comparable stabilities at finite temperatures. (C) 2012 Elsevier B. V. All rights reserved. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000313644100032 | Publication Date | 2012-11-28 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0009-2614; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.815 | Times cited | 3 | Open Access | |
Notes | Approved | Most recent IF: 1.815; 2013 IF: 1.991 | |||
Call Number | UA @ lucian @ c:irua:110085 | Serial | 3132 | ||
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Author | Scipioni, R.; Matsubara, M.; Ruiz, E.; Massobrio, C.; Boero, M. | ||||
Title | Thermal behavior of Si-doped fullerenes vs their structural stability at T = 0 K : a density functional study | Type | A1 Journal article | ||
Year | 2011 | Publication | Chemical physics letters | Abbreviated Journal | Chem Phys Lett |
Volume | 510 | Issue | 1/3 | Pages | 14-17 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | We establish the topological conditions underlying the thermal stability of C30Si30 clusters. Two topologies have been considered: a segregated one, where Si and C atoms lie on neighboring and yet, separated parts of the cage, and a non-segregated one, where the number of SiC bonds is maximized. The segregated network is energetically favored against the non-segregated one, both structures being fully relaxed at T = 0 K. Conversely, the non-segregated structure is the only one stable at finite temperatures, regardless of the nature of the local states (d or p) included in the KleynmanBylander construction. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Amsterdam | Editor | ||
Language | Wos | 000291478400002 | Publication Date | 2011-05-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0009-2614; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.815 | Times cited | 14 | Open Access | |
Notes | Approved | Most recent IF: 1.815; 2011 IF: 2.337 | |||
Call Number | UA @ lucian @ c:irua:90453 | Serial | 3625 | ||
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Author | Matsubara, M.; Amini, M.N.; Saniz, R.; Lamoen, D.; Partoens, B. | ||||
Title | Attracting shallow donors : hydrogen passivation in (Al,Ga,In)-doped ZnO | Type | A1 Journal article | ||
Year | 2012 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 86 | Issue | 16 | Pages | 165207 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | The hydrogen interstitial and the substitutional AlZn, GaZn, and InZn are all shallow donors in ZnO and lead to n-type conductivity. Although shallow donors are expected to repel each other, we show by first-principles calculations that in ZnO these shallow donor impurities attract and form a complex, leading to a donor level deep in the band gap. This puts a limit on the n-type conductivity of (Al,Ga,In)-doped ZnO in the presence of hydrogen. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000310131300008 | Publication Date | 2012-10-22 | |
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 | 7 | Open Access | |
Notes | Iwt; Fwo; Bof-Noi | Approved | Most recent IF: 3.836; 2012 IF: 3.767 | ||
Call Number | UA @ lucian @ c:irua:101780 | Serial | 202 | ||
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Author | Saniz, R.; Xu, Y.; Matsubara, M.; Amini, M.N.; Dixit, H.; Lamoen, D.; Partoens, B. | ||||
Title | A simplified approach to the band gap correction of defect formation energies : Al, Ga, and In-doped ZnO | Type | A1 Journal article | ||
Year | 2013 | Publication | The journal of physics and chemistry of solids | Abbreviated Journal | J Phys Chem Solids |
Volume | 74 | Issue | 1 | Pages | 45-50 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | The calculation of defect levels in semiconductors within a density functional theory approach suffers greatly from the band gap problem. We propose a band gap correction scheme that is based on the separation of energy differences in electron addition and relaxation energies. We show that it can predict defect levels with a reasonable accuracy, particularly in the case of defects with conduction band character, and yet is simple and computationally economical. We apply this method to ZnO doped with group III elements (Al, Ga, In). As expected from experiment, the results indicate that Zn substitutional doping is preferred over interstitial doping in Al, Ga, and In-doped ZnO, under both zinc-rich and oxygen-rich conditions. Further, all three dopants act as shallow donors, with the +1 charge state having the most advantageous formation energy. Also, doping effects on the electronic structure of ZnO are sufficiently mild so as to affect little the fundamental band gap and lowest conduction bands dispersion, which secures their n-type transparent conducting behavior. A comparison with the extrapolation method based on LDA+U calculations and with the HeydScuseriaErnzerhof hybrid functional (HSE) shows the reliability of the proposed scheme in predicting the thermodynamic transition levels in shallow donor systems. | ||||
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Publisher | Place of Publication | New York, N.Y. | Editor | ||
Language | Wos | 000311062500009 | Publication Date | 2012-08-10 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0022-3697; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.059 | Times cited | 36 | Open Access | |
Notes | Fwo; Bof-Nio | Approved | Most recent IF: 2.059; 2013 IF: 1.594 | ||
Call Number | UA @ lucian @ c:irua:101782 | Serial | 3004 | ||
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Author | Matsubara, M.; Saniz, R.; Partoens, B.; Lamoen, D. | ||||
Title | Doping anatase TiO2with group V-b and VI-b transition metal atoms: a hybrid functional first-principles study | Type | A1 Journal article | ||
Year | 2017 | Publication | Physical chemistry, chemical physics | Abbreviated Journal | Phys Chem Chem Phys |
Volume | 19 | Issue | 19 | Pages | 1945-1952 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
Abstract | We investigate the role of transition metal atoms of group V-b (V, Nb, Ta) and VI-b (Cr, Mo, W) as n- or p-type dopants in anatase TiO$2$ using thermodynamic principles and density functional theory with the Heyd-Scuseria-Ernzerhof HSE06 hybrid functional. The HSE06 functional provides a realistic value for the band gap, which ensures a correct classification of dopants as shallow or deep donors or acceptors. Defect formation energies and thermodynamic transition levels are calculated taking into account the constraints imposed by the stability of TiO$2$ and the solubility limit of the impurities. Nb, Ta, W and Mo are identified as shallow donors. Although W provides two electrons, Nb and Ta show a considerable lower formation energy, in particular under O-poor conditions. Mo donates in principle one electron, but under specific conditions can turn into a double donor. V impurities are deep donors and Cr shows up as an amphoteric defect, thereby acting as an electron trapping center in n-type TiO$_2$ especially under O-rich conditions. A comparison with the available experimental data yields excellent agreement. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000394426400027 | Publication Date | 2016-12-12 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1463-9076 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.123 | Times cited | 19 | Open Access | OpenAccess |
Notes | We gratefully acknowledge financial support from the IWTVlaanderenthrough projects G.0191.08 and G.0150.13, and the BOF-NOI of the University of Antwerp. This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center VSC, which is funded by the Hercules foundation. M. M. acknowledges financial support from the GOA project ‘‘XANES meets ELNES’’ of the University of Antwerp. | Approved | Most recent IF: 4.123 | ||
Call Number | EMAT @ emat @ c:irua:140835 | Serial | 4421 | ||
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