| Journal: | Brazilian journal of physics |
| Database: | PERIÓDICA |
| System number: | 000361840 |
| ISSN: | 0103-9733 |
| Authors: | Schilling, OSvaldo F1 |
| Institutions: | 1Universidade Federal de Santa Catarina, Departamento de Fisica, Florianopolis, Santa Catarina. Brasil |
| Year: | 2013 |
| Season: | Ago |
| Volumen: | 43 |
| Number: | 4 |
| Pages: | 214-222 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Experimental, aplicado |
| English abstract | A wealth of experimental and theoretical data on the crystallographic and magnetic properties of the magnetocaloric compounds MnFeAsxP1− x (0.25≤x≤ 0.65) and MnFeAs has become available in the last decade. By analyzing the data and treating the spin interactions with Callen’s cluster expansion method, we extrapolate first-principle results for the exchangecoupling constants of MnFeAs to the P-substituted compounds and find Curie temperatures that agree, within 5 % deviation, with experiment. Simulations with different coupling parameters show that Tc is weakly dependent on the Fe–Fe interactions. Analysis of lattice expansion as a function of composition shows that changes in the lattice parameters a and c have opposite effects upon the strength of the magnetic interactions between ions. The results indicate that the cluster expansion method provides reliable estimates of magnetic properties, even for metallic compounds characterized by multiple interactions among ions with distinct magnetic moments |
| Disciplines: | Física y astronomía |
| Keyword: | Física de materia condensada, Efecto magnetocalórico, Modelo de Heisenberg, Aproximación de acoplamiento constante |
| Keyword: | Physics and astronomy, Condensed matter physics, Magnetocaloric effect, Heisenberg model, Constant coupling approximation |
| Full text: | Texto completo (Ver HTML) |
