کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1482616 | 1510486 | 2010 | 5 صفحه PDF | دانلود رایگان |
A polymer precursor method has been used to synthesize Ni-doped SnO2 nanoparticles. X-ray diffraction (XRD) data analyses indicate the exclusive formation of nanosized particles with rutile-type phase (tetragonal SnO2) for Ni contents below 10 mol%. In this concentration range, the particle sizes decrease with increasing Ni content and a bulk solid solution limit was determined at ~ 1 mol%. Ni surface enrichment is present at concentrations higher than the solution limit. Only above 10 mol% Ni, the formation of a second NiO-related phase has been determined. Magnetization measurements suggest the occurrence of ferromagnetism for samples in the solid solution regime (below ~ 1 mol%). This ferromagnetism is associated with the exchange interaction between electron spins trapped on oxygen vacancies, and is enhanced as the amount of Ni2+ substituting at Sn4+ sites increases. Above the solid solution limit, ferromagnetism is destroyed by the Ni surface enrichment and the system behaves as a paramagnet.
Journal: Journal of Non-Crystalline Solids - Volume 356, Issues 52–54, December 2010, Pages 2960–2964