Particle size effects on magnetic properties of yttrium iron garnets prepared by a sol-gel method

We present detailed measurements of field - and temperature - dependence of magnetization in nanocrystalline YIG (Y3Fe5O12) particles. The fine powders were prepared using sol-gel method. Samples with particle sizes ranging from 45 to 450 nm were obtained. We observe that the saturation magnetizatio...

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Detalles Bibliográficos
Autores: Sanchez, Rodolfo Daniel, Rivas, J., Vaqueiro, P., López Quintela, M. A., Caeiro, D.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2002
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/68575
Acceso en línea:http://hdl.handle.net/11336/68575
Access Level:acceso abierto
Palabra clave:Magnetic Properties
Small Particles
Yttrium Iron Garnet
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descripción
Sumario:We present detailed measurements of field - and temperature - dependence of magnetization in nanocrystalline YIG (Y3Fe5O12) particles. The fine powders were prepared using sol-gel method. Samples with particle sizes ranging from 45 to 450 nm were obtained. We observe that the saturation magnetization decreases as the particle size is reduced due to enhancement of the surface spin effects. Below a critical diameter Ds ≅ 190 nm, the particles become single domains and the coercive forces reaches a maximum at diameters close to the critical value. As the particle size decreases the coercivity diminishes and at Dp ≃ 35 nm diameters the upper limit of superparamagnetic behavior is reached. A quantitative comparison of temperature and particle size dependence of coercivity shows a satisfactory agreement that is expected for an assembly of randomly oriented particles.