Study of the oxygen vacancy influence on magnetic properties of Fe- and Co-doped SnO2 diluted alloys.

Content Provider	Europe PMC
Author	Borges, Pablo D Scolfaro, Luisa M R Alves, Horacio W Leite da Silva, Eronides F Assali, Lucy V C
Copyright Year	2012
Abstract	Transition-metal (TM)-doped diluted magnetic oxides (DMOs) have attracted attention from both experimental and theoretical points of view due to their potential use in spintronics towards new nanostructured devices and new technologies. In the present work, we study the magnetic properties of Sn0.96TM0.04O2 and Sn0.96TM0.04O1.98(VO)0.02, where TM = Fe and Co, focusing in particular in the role played by the presence of O vacancies nearby the TM. The calculated total energy as a function of the total magnetic moment per cell shows a magnetic metastability, corresponding to a ground state, respectively, with 2 and 1 μB/cell, for Fe and Co. Two metastable states, with 0 and 4 μB/cell were found for Fe, and a single value, 3 μB/cell, for Co. The spin-crossover energies (ES) were calculated. The values are ES0/2 = 107 meV and ES4/2 = 25 meV for Fe. For Co, ES3/1 = 36 meV. By creating O vacancies close to the TM site, we show that the metastablity and ES change. For iron, a new state appears, and the state with zero magnetic moment disappears. The ground state is 4 μB/cell instead of 2 μB/cell, and the energy ES2/4 is 30 meV. For cobalt, the ground state is then found with 3 μB/cell and the metastable state with 1 μB/cell. The spin-crossover energy ES1/3 is 21 meV. Our results suggest that these materials may be used in devices for spintronic applications that require different magnetization states.
ISSN	19317573
Journal	Nanoscale Research Letters
Volume Number	7
PubMed Central reference number	PMC3492107
Issue Number	1
PubMed reference number	23020790
e-ISSN	1556276X
DOI	10.1186/1556-276x-7-540
Language	English
Publisher	Springer
Publisher Date	2012-09-28
Access Restriction	Open
Rights License	This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright ©2012 Borges et al.; licensee Springer.
Subject Keyword	Tin dioxide Diluted magnetic semiconductors Magnetic properties ab initio calculations Electronic structure
Content Type	Text
Resource Type	Article
Subject	Nanoscience and Nanotechnology Condensed Matter Physics Materials Science