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Author Ray, S.; Kolen'ko, Y.V.; Kovnir, K.A.; Lebedev, O.I.; Turner, S.; Chakraborty, T.; Erni, R.; Watanabe, T.; Van Tendeloo, G.; Yoshimura, M.; Itoh, M.
Title Defect controlled room temperature ferromagnetism in Co-doped barium titanate nanocrystals Type A1 Journal article
Year (up) 2012 Publication Nanotechnology Abbreviated Journal Nanotechnology
Volume 23 Issue 2 Pages 025702,1-025702,10
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Defect mediated high temperature ferromagnetism in oxide nanocrystallites is the central feature of this work. Here, we report the development of room temperature ferromagnetism in nanosized Co-doped barium titanate particles with a size of around 14 nm, synthesized by a solvothermal drying method. A combination of x-ray diffraction with state-of-the-art electron microscopy techniques confirms the intrinsic doping of Co into BaTiO3. The development of the room temperature ferromagnetism was tracked down to the different donor defects, namely hydroxyl groups at the oxygen site (\mathrm {OH}\mathrm {(O)}
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Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000298409000011 Publication Date 2011-12-14
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 19 Open Access
Notes Esteem 026019; Fwo Approved Most recent IF: 3.44; 2012 IF: 3.842
Call Number UA @ lucian @ c:irua:93636 Serial 614
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Author Zarenia, M.; Partoens, B.; Chakraborty, T.; Peeters, F.M.
Title Electron-electron interactions in bilayer graphene quantum dots Type A1 Journal article
Year (up) 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 88 Issue 24 Pages 245432-245435
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A parabolic quantum dot (QD) as realized by biasing nanostructured gates on bilayer graphene is investigated in the presence of electron-electron interaction. The energy spectrum and the phase diagram reveal unexpected transitions as a function of a magnetic field. For example, in contrast to semiconductor QDs, we find a valley transition rather than only the usual singlet-triplet transition in the ground state of the interacting system. The origin of these features can be traced to the valley degree of freedom in bilayer graphene. These transitions have important consequences for cyclotron resonance experiments.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000328688600010 Publication Date 2014-01-09
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 29 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES program EuroGRAPHENE (project CONGRAN), and the Methusalem foundation of the Flemish Government. T. C. is supported by the Canada Research Chairs program of the Government of Canada. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
Call Number UA @ lucian @ c:irua:113698 Serial 926
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Author Mary Joy, R.; Pobedinskas, P.; Bourgeois, E.; Chakraborty, T.; Görlitz, J.; Herrmann, D.; Noël, C.; Heupel, J.; Jannis, D.; Gauquelin, N.; D'Haen, J.; Verbeeck, J.; Popov, C.; Houssiau, L.; Becher, C.; Nesládek, M.; Haenen, K.
Title Germanium vacancy centre formation in CVD nanocrystalline diamond using a solid dopant source Type A3 Journal article
Year (up) 2023 Publication Science talks Abbreviated Journal Science Talks
Volume 5 Issue Pages 100157
Keywords A3 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2023-02-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2772-5693 ISBN Additional Links UA library record
Impact Factor Times cited Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:196969 Serial 8791
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Author Joy, R.M.; Pobedinskas, P.; Bourgeois, E.; Chakraborty, T.; Goerlitz, J.; Herrmann, D.; Noel, C.; Heupel, J.; Jannis, D.; Gauquelin, N.; D'Haen, J.; Verbeeck, J.; Popov, C.; Houssiau, L.; Becher, C.; Nesladek, M.; Haenen, K.
Title Photoluminescence of germanium-vacancy centers in nanocrystalline diamond films : implications for quantum sensing applications Type A1 Journal article
Year (up) 2024 Publication ACS applied nano materials Abbreviated Journal
Volume 7 Issue 4 Pages 3873-3884
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Point defects in diamond, promising candidates for nanoscale pressure- and temperature-sensing applications, are potentially scalable in polycrystalline diamond fabricated using the microwave plasma-enhanced chemical vapor deposition (MW PE CVD) technique. However, this approach introduces residual stress in the diamond films, leading to variations in the characteristic zero phonon line (ZPL) of the point defect in diamond. Here, we report the effect of residual stress on germanium-vacancy (GeV) centers in MW PE CVD nanocrystalline diamond (NCD) films fabricated using single crystal Ge as the substrate and solid dopant source. GeV ensemble formation indicated by the zero phonon line (ZPL) at similar to 602 nm is confirmed by room temperature (RT) photoluminescence (PL) measurements. PL mapping results show spatial nonuniformity in GeV formation along with other defects, including silicon-vacancy centers in the diamond films. The residual stress in NCD results in shifts in the PL peak positions. By estimating a stress shift coefficient of (2.9 +/- 0.9) nm/GPa, the GeV PL peak position in the NCD film is determined to be between 598.7 and 603.2 nm. A larger ground state splitting due to the strain on a GeV-incorporated NCD pillar at a low temperature (10 K) is also reported. We also report the observation of intense ZPLs at RT that in some cases could be related to low Ge concentration and the surrounding crystalline environment. In addition, we also observe thicker microcrystalline diamond (MCD) films delaminate from the Ge substrate due to film residual stress and graphitic phase at the diamond/Ge substrate interface (confirmed by electron energy loss spectroscopy). Using this approach, a free-standing color center incorporated MCD film with dimensions up to 1 x 1 cm(2) is fabricated. Qualitative analysis using time-of-flight secondary ion mass spectroscopy reveals the presence of impurities, including Ge and silicon, in the MCD film. Our experimental results will provide insights into the scalability of GeV fabrication using the MW PE CVD technique and effectively implement NCD-based nanoscale-sensing applications.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001164609600001 Publication Date 2024-02-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2574-0970 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:204826 Serial 9164
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