Structural and magnetic properties of Gd-doped ZnO

Handle URI:
http://hdl.handle.net/10754/563264
Title:
Structural and magnetic properties of Gd-doped ZnO
Authors:
Bantounas, Ioannis; Singaravelu, Venkatesh; Roqan, Iman S. ( 0000-0001-7442-4330 ) ; Schwingenschlögl, Udo ( 0000-0003-4179-7231 )
Abstract:
We use density functional theory to investigate structural and magnetic properties of Gd doped ZnO, accounting for the impurity 4f states using the GGA + U method. (i) We calculate the binding energy of forming [Gd-Gd] dimers, [VO - GdZn] and [VZn - GdZn] complexes and find that while the formation of [VZn - GdZn] is favourable, [GdZn - GdZn] and [VO - GdZn] complexes are less likely to form. Next, (ii) we investigate the spacial arrangement of two (and three) GdZn impurities in a 3 × 3 × 2 supercell and find that the magnetic impurities are energetically favourable when occupying distant lattice sites. Finally, we study the nature of interactions between the magnetic impurities (iii) for Gd in nearest-neighbour and non-nearest-neighbour Zn sites, (iv) in the presence of Zn or O vacancies, and (v) with and without additional charge carriers. Our results show mainly paramagnetic behaviour. In a few cases, e.g. magnetic impurities occupying in-plane nearest-neighbour zinc sites with n-type carrier doping, weak ferromagnetic coupling is observed. This magnetic ordering is of the order of a few meV and can be easily destroyed by thermal fluctuations. We thus expect Gd:ZnO to show paramagnetic behaviour at temperatures approaching room temperature.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; Materials Science and Engineering Program; Semiconductor and Material Spectroscopy (SMS) Laboratory; Computational Physics and Materials Science (CPMS)
Publisher:
Royal Society of Chemistry (RSC)
Journal:
J. Mater. Chem. C
Issue Date:
2014
DOI:
10.1039/c4tc01237b
Type:
Article
ISSN:
20507534
Sponsors:
Research reported in this publication was supported by the King Abdullah University of Science and Technology (KAUST). The authors would like to acknowledge the computational resources provided by KAUST IT Research Computing, and wish to thank C. Kapfer for his continuous support throughout this project.
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Materials Science and Engineering Program; Computational Physics and Materials Science (CPMS)

Full metadata record

DC FieldValue Language
dc.contributor.authorBantounas, Ioannisen
dc.contributor.authorSingaravelu, Venkateshen
dc.contributor.authorRoqan, Iman S.en
dc.contributor.authorSchwingenschlögl, Udoen
dc.date.accessioned2015-08-03T11:44:25Zen
dc.date.available2015-08-03T11:44:25Zen
dc.date.issued2014en
dc.identifier.issn20507534en
dc.identifier.doi10.1039/c4tc01237ben
dc.identifier.urihttp://hdl.handle.net/10754/563264en
dc.description.abstractWe use density functional theory to investigate structural and magnetic properties of Gd doped ZnO, accounting for the impurity 4f states using the GGA + U method. (i) We calculate the binding energy of forming [Gd-Gd] dimers, [VO - GdZn] and [VZn - GdZn] complexes and find that while the formation of [VZn - GdZn] is favourable, [GdZn - GdZn] and [VO - GdZn] complexes are less likely to form. Next, (ii) we investigate the spacial arrangement of two (and three) GdZn impurities in a 3 × 3 × 2 supercell and find that the magnetic impurities are energetically favourable when occupying distant lattice sites. Finally, we study the nature of interactions between the magnetic impurities (iii) for Gd in nearest-neighbour and non-nearest-neighbour Zn sites, (iv) in the presence of Zn or O vacancies, and (v) with and without additional charge carriers. Our results show mainly paramagnetic behaviour. In a few cases, e.g. magnetic impurities occupying in-plane nearest-neighbour zinc sites with n-type carrier doping, weak ferromagnetic coupling is observed. This magnetic ordering is of the order of a few meV and can be easily destroyed by thermal fluctuations. We thus expect Gd:ZnO to show paramagnetic behaviour at temperatures approaching room temperature.en
dc.description.sponsorshipResearch reported in this publication was supported by the King Abdullah University of Science and Technology (KAUST). The authors would like to acknowledge the computational resources provided by KAUST IT Research Computing, and wish to thank C. Kapfer for his continuous support throughout this project.en
dc.publisherRoyal Society of Chemistry (RSC)en
dc.titleStructural and magnetic properties of Gd-doped ZnOen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentMaterials Science and Engineering Programen
dc.contributor.departmentSemiconductor and Material Spectroscopy (SMS) Laboratoryen
dc.contributor.departmentComputational Physics and Materials Science (CPMS)en
dc.identifier.journalJ. Mater. Chem. Cen
kaust.authorBantounas, Ioannisen
kaust.authorSingaravelu, Venkateshen
kaust.authorRoqan, Iman S.en
kaust.authorSchwingenschlögl, Udoen
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