Room temperature ferromagnetism in vacuum annealed ZnFe2O4 nanoparticles

被引：89

作者：

Ayyappan, S. ^{[1
]}

Raja, S. Philip ^{[2
]}

Venkateswaran, C. ^{[2
]}

Philip, John ^{[1
]}

Raj, Baldev ^{[1
]}

机构：

[1] Indira Gandhi Ctr Atom Res, Met & Mat Grp, Kalpakkam 603102, Tamil Nadu, India

[2] Univ Madras, Dept Nucl Phys, Madras 600025, Tamil Nadu, India

来源：

APPLIED PHYSICS LETTERS | 2010年 / 96卷 / 14期

关键词：

annealing; ferromagnetic materials; interstitials; magnetic particles; magnetic switching; magnetisation; Mossbauer effect; nanoparticles; paramagnetic materials; Raman spectra; vacancies (crystal); zinc compounds; NANOSIZE ZINC FERRITE; FINE POWDERS; MAGNETISM; SITES;

D O I：

10.1063/1.3374332

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We report room temperature ferromagnetism in vacuum annealed ZnFe2O4 (ZFO) nanoparticles. Upon vacuum and air annealing, ZFO nanoparticles show ferro and paramagnetic behavior, respectively. The well defined sextets along with doublet seen in the Mossbauer spectra confirms ferromagnetic coupling in vacuum annealed ZFO. After reannealing in air, the magnetization of vacuum annealed sample reduces from 62 to 1.5 emu/g. Both Mossbauer and micro-Raman results suggest that oxygen vacancies generated during vacuum annealing causes cation redistribution between the interstitial sites resulting in magnetic ordering. Our results show a unique possibility of switching the magnetic properties of ZFO between paramagnetic to ferromagnetic.

引用

页数：3

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