Coercivity and its thermal dependence in microsized magnetic particles: Influence of grain boundaries

Fe_(73.5)Si_(13.5)B_9Nb_3Cu_1 powder particles have been obtained by gas atomization. Magnetization curves and coercivity were studied for particles ranging in size up to 1000μ. The overall magnetic behavior of such material is consequence of compositional heterogeneity of the microstructure as a wh...

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Detalles Bibliográficos
Autores: Marín Palacios, María Pilar, Aragón, A. M, Garcia Escoria, A., Lieblich, M., Crespo del Arco, Patricia, Hernando Grande, Antonio
Tipo de recurso: artículo
Fecha de publicación:2013
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/35406
Acceso en línea:https://hdl.handle.net/20.500.14352/35406
Access Level:acceso abierto
Palabra clave:538.9
Fe-Cu
Nanocrystalline Fe
Alloys
Soft
Anisotropy
Mossbauer
Behavior
Wires
Iron.
Física de materiales
Descripción
Sumario:Fe_(73.5)Si_(13.5)B_9Nb_3Cu_1 powder particles have been obtained by gas atomization. Magnetization curves and coercivity were studied for particles ranging in size up to 1000μ. The overall magnetic behavior of such material is consequence of compositional heterogeneity of the microstructure as a whole. Anomalous temperature variation of coercivity (H_c) (i.e., a decrease in H_c with decreasing temperature) together with a decrease of saturation magnetization has been observed for less than 25 μm size. The origin of this behavior has been ascribed to metastable FeCu and FeNbSi phases in combination with an Fe-rich one. Making magnetic powders with coercive fields of the order of mOe remains a challenge for researchers. Our experiment has allowed us, at low temperature, achieving a coercive field of 9 Oe, much lower than those observed so far in this type of materials. This behaviour has been related with a FeCu phase present on grain boundaries.