Rotatable anisotropy driven training effects in exchange biased Co/CoO films

The training effect for exchange bias in field-cooled Co/CoO bilayers films is investigated. Previous experiments on the same system have shown that, starting from the ascending branch of the first hysteresis loop, coherent magnetization rotation is the dominant reversal mechanism. This is confirmed...

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Detalles Bibliográficos
Autores: Dias, Thiago, Menéndez Dalmau, Enric, Liu, Haoliang, Van Haesendonck, Christian, Vantomme, A., Temst, Kristiaan, Schmidt, Joao Edgar, Giulian, Raquel, Geshev, Julian Penkov
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:Brasil
Institución:Universidade Federal do Rio Grande do Sul (UFRGS)
Repositorio:Repositório Institucional da UFRGS
Idioma:inglés
OAI Identifier:oai:www.lume.ufrgs.br:10183/107857
Acceso en línea:http://hdl.handle.net/10183/107857
Access Level:acceso abierto
Palabra clave:Filmes finos magneticos
Anisotropia magnética
Reversão de magnetização
Materiais ferromagnéticos
Magnetismo de interface
Forca coerciva
Histerese magnética
Compostos de cobalto
Descripción
Sumario:The training effect for exchange bias in field-cooled Co/CoO bilayers films is investigated. Previous experiments on the same system have shown that, starting from the ascending branch of the first hysteresis loop, coherent magnetization rotation is the dominant reversal mechanism. This is confirmed by the performed numerical simulations, which also indicate that the training is predominantly caused by changes of the rotatable anisotropy parameters of uncompensated spins at the Co/CoO interface. Moreover, in contrast with what is commonly assumed, the exchange coupling between the rotatable spins and the ferromagnetic layer is stronger than the coupling between the ferromagnet and the spins responsible for the bias. Thus, uncompensated spins strongly coupled to the ferromagnet contribute to the coercivity rather than to the bias, whatever the strength of their magnetic anisotropy.