Effect of Mo/W disorder on the Curie temperature of Sr2FeMoxW1−xO6 double perovskite
The double perovskites Sr2FeMO6 have received a lot of attention, especially Sr2FeMoO6 because of its fairly high Curie temperature (TC = 450 K), half-metallic character, large magnetoresistance and potential applications. On the other hand, Sr2FeWO6 is insulating and antiferromagnetic with TN = 37...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2007 |
| País: | México |
| Institución: | Universidad Nacional Autónoma de México |
| Repositorio: | Redalyc-UNAM |
| OAI Identifier: | oai:redalyc.org:57036163034 |
| Acceso en línea: | https://www.redalyc.org/articulo.oa?id=57036163034 |
| Access Level: | acceso abierto |
| Palabra clave: | Física, Astronomía y Matemáticas metal insulator transitions Colossal magnetoresistance general theory and models of magnetic ordering |
| Sumario: | The double perovskites Sr2FeMO6 have received a lot of attention, especially Sr2FeMoO6 because of its fairly high Curie temperature (TC = 450 K), half-metallic character, large magnetoresistance and potential applications. On the other hand, Sr2FeWO6 is insulating and antiferromagnetic with TN = 37 K. With a double exchange type model it has been shown that a ferromagnetic-antiferromagnetic transition can be driven by super-exchange interactions with increasing Fe-M (M=Mo,W) charge transfer energy. Therefore, the charge transfer energy is expected to be larger in FeW than in FeMo compounds. The effect of the Mo/W diagonal disorder in Sr2FeMoxW1−xO6 has been studied using the tight-binding model and the renormalization perturbation expansion method. For different values of the disorder we calculate the density of states and determine the behavior of the Curie temperature as a function of the Mo/W concentration. The magnetic and the electronic properties in these compounds are discussed in view of these results. |
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