Origin of spin-glass and exchange bias in La1-3Sr2-3FeO3−γ nanoparticles
The structure and the magnetic properties of nanopowdered samples of La1=3Sr2=3FeO3c with average particles size d in the range of 67-367 nm prepared by a sol-gel method were investigated in detail. The samples were characterized by X-ray diffraction, scanning electron microscopy, specific heat, M€o...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2014 |
| País: | Brasil |
| Institución: | Universidade Federal do Rio Grande do Norte (UFRN) |
| Repositorio: | Repositório Institucional da UFRN |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.ufrn.br:123456789/29365 |
| Acceso en línea: | https://repositorio.ufrn.br/jspui/handle/123456789/29365 |
| Access Level: | acceso abierto |
| Palabra clave: | Spin-glass Exchange bias Nanoparticles |
| Sumario: | The structure and the magnetic properties of nanopowdered samples of La1=3Sr2=3FeO3c with average particles size d in the range of 67-367 nm prepared by a sol-gel method were investigated in detail. The samples were characterized by X-ray diffraction, scanning electron microscopy, specific heat, M€ossbauer spectroscopy, ac susceptibility, and magnetization measurements. Exchange bias with vertical magnetization shift was found in all samples. Charge ordering and antiferromagnetism were observed close to 200 K for large particles (d 304 nm) samples, while for particles with intermediated and smaller values (d 156 nm) a cluster-glass like behaviour and a short range charge ordering were seen near 115 K and 200 K, respectively. The spin-glass like and exchange bias behaviour in nanopowdered samples of La1=3Sr2=3FeO3c are associated to compact Fe3þ antiferromagnetic (AF) clusters caused by an oxygen deficiency, which was found to be higher in the samples with the smallest average particles sizes. The effect of exchange bias and vertical magnetization shifts are explained by a simple model involving the interaction of one AF phase with a canted AF phase |
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