| Autor: |
Galina V. Bondarenko, V. V. Rudenko, V. I. Tugarinov, A. M. Vorotynov, Sergey Ovchinnikov, V. M. Sosnin |
| Rok vydání: |
2013 |
| Předmět: |
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| Zdroj: |
Journal of Magnetism and Magnetic Materials. 335:90-96 |
| ISSN: |
0304-8853 |
| DOI: |
10.1016/j.jmmm.2013.01.037 |
| Popis: |
The method for investigation of the uniaxial and hexagonal anisotropies in weakly ferromagnetic rhombohedral FeBO 3 crystals with the Fe 2+ magnetic impurity with the use of the single-ion and pair approximation has been developed. In the framework of this method, a quantitative discrepancy between theoretical and experimental data on a uniaxial field has been eliminated. The energy contributions to the hexagonal anisotropy that are caused by the Dzyaloshinsky–Moriya interaction, the crystal field of Fe 3+ ions and the temperature dependence of this anisotropy were analytically treated. The experimental temperature dependence of the hexagonal anisotropy of FeBO 3 crystals is explained. It is shown that the compensation point and the typical temperature dependence of the hexagonal anisotropy result from the competition of the contributions of Fe 3+ and Fe 2+ ions. It is shown that respective considerable contributions to the anisotropy of Fe 3+ and Fe 2+ ions are made by the cubic symmetry and the uniaxial symmetry of the exchange “single-ion” type. The anisotropy constants for FeBO 3 crystal was obtained by using the described results. It was shown, that for the calcite type structure crystals (iron borate and manganese carbonate) with S -state ions, the single ion and pair models (which previously raised doubts in their validity and accuracy) describe the experimental data good enough. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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