Shifted loops and coercivity from field-imprinted high-energy barriers in ferritin and ferrihydrite nanoparticles

We show that the coercive field in ferritin and ferrihydrite depends on the maximum magnetic field in a hysteresis loop and that coercivity and loop shifts depend both on the maximum and cooling fields. In the case of ferritin, we show that the time dependence of the magnetization also depends on th...

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Detalhes bibliográficos
Autores: Silva, N. J. O., Amaral,V. S., Urtizberea,A., Bustamante,R., Millán,A., Palacio,F., Kampert,E., Zeitler,U., De Brion,S., Iglesias,A. A., Labarta,A.
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2011
País:España
Recursos:Universidad de Zaragoza
Repositorio:Zaguán. Repositorio Digital de la Universidad de Zaragoza
OAI Identifier:oai:zaguan.unizar.es:132258
Acesso em linha:http://zaguan.unizar.es/record/132258
Access Level:acceso abierto
Descrição
Resumo:We show that the coercive field in ferritin and ferrihydrite depends on the maximum magnetic field in a hysteresis loop and that coercivity and loop shifts depend both on the maximum and cooling fields. In the case of ferritin, we show that the time dependence of the magnetization also depends on the maximum and previous cooling fields. This behavior is associated to changes in the intraparticle energy barriers imprinted by these fields. Accordingly, the dependence of the coercive and loop-shift fields with the maximum field in ferritin and ferrihydrite can be described within the frame of a uniform-rotation model considering a dependence of the energy barrier with the maximum and the cooling fields.

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