Non-thermal viscosity in magnets: Quantum Tunneling of the Magnetization

In this article we present experimental results on the magnetic relaxation in different systems (single domain particles, magnetic grains, and random magnets). The existence of two relaxation regimes is demonstrated. At high temperatures, the magnetic viscosity S≡1/M0∂M/∂ ln(t) is proportional to te...

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Detalles Bibliográficos
Autores: Tejada Palacios, Javier, Zhang, Xixiang, Balcells i Argemí, Lluís
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:1993
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/22104
Acceso en línea:https://hdl.handle.net/2445/22104
Access Level:acceso abierto
Palabra clave:Materials magnètics
Propietats magnètiques
Ressonància magnètica
Matèria condensada
Efecte Mössbauer
Magnetic materials
Magnetic properties
Magnetic resonance
Condensed matter
Mössbauer effect
Descripción
Sumario:In this article we present experimental results on the magnetic relaxation in different systems (single domain particles, magnetic grains, and random magnets). The existence of two relaxation regimes is demonstrated. At high temperatures, the magnetic viscosity S≡1/M0∂M/∂ ln(t) is proportional to temperature in accordance with theoretical expectation for thermally activated processes. At low temperatures, the viscosity is independent of temperature, providing evidence to quantum tunneling of magnetization. Qualitative agreement between theory and experiment is found.