Field dependence of the magnetocaloric effect in materials with a second order phase transition: A master curve for the magnetic entropy change
The field dependence of the magnetic entropy change can be expressed as SM Hn. For soft magnetic amorphous alloys n=1 well below the Curie temperature TC , n=2 in the paramagnetic range, and n 0.75 for T=TC. The first value can be explained with simple arguments, n=2 is a consequence of the Curie-We...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2006 |
| País: | España |
| Institución: | Universidad de Sevilla (US) |
| Repositorio: | idUS. Depósito de Investigación de la Universidad de Sevilla |
| OAI Identifier: | oai:idus.us.es:11441/33352 |
| Acceso en línea: | http://hdl.handle.net/11441/33352 https://doi.org/10.1063/1.2399361 |
| Access Level: | acceso abierto |
| Palabra clave: | Entropy Magnetic field effects Phase transitions Thermal effects |
| Sumario: | The field dependence of the magnetic entropy change can be expressed as SM Hn. For soft magnetic amorphous alloys n=1 well below the Curie temperature TC , n=2 in the paramagnetic range, and n 0.75 for T=TC. The first value can be explained with simple arguments, n=2 is a consequence of the Curie-Weiss law, but n TC deviates from mean field predictions. From the Arrott-Noakes equation of state, a relation between n TC and the critical exponents has been obtained, showing remarkable agreement with experimental data for an example alloy, predicted n=0.72 versus experimental n=0.73 . A master curve behavior for the temperature dependence of SM measured for different maximum fields is proposed. |
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