Regensburg 2019 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 23: Soft and hard permanent bulk magnets

MA 23.2: Vortrag

Dienstag, 2. April 2019, 14:15–14:30, H53

Ab initio Study of Magnetic Properties of Rare-Earth lean 1:12 Alloys — •Olga Vekilova¹, Olle Eriksson^1,2, and Heike C. Herper¹ — ¹Department of Physics and Astronomy, Uppsala University — ²School of Science and Technology, Orebro University

Since the discovery of Nd₂Fe₁₄B, the best permanent magnet to date, magnets containing the combination of rare earth elements and Fe attract high scientific interest. The iron-rich compounds are specifically attractive as they have large magnetic moments due to the high concentration of Fe, rather high coercivity and high Curie temperature. One of the best candidates are the 1:12 compounds with the ThMn₁₂-type structure. It has been shown that light rare earths and iron cannot form a stable binary 1:12 compound, so a third element must be added to stabilize the ternary RE(Fe,M)₁₂ phase, where M=Ti, V, Si, Mo and etc. Such substitution results in a significant decrease in the saturation magnetization and can influence magnetocrystalline anisotropy and Curie temperature of the alloy. Recent experiments show that it is possible to stabilize the 1:12 phases with reduced concentrations of M. Magnetic properties of the 1:12 compounds were studied theoretically from first principles. Starting from the known stable SmFe₁₀V₂ and NdFe₁₁Ti we improved the magnetic properties by reducing the content of V and Ti respectively. The phase stabilities, magnetizations, Curie temperature, magnetocrystalline anisotropies of NdFe_12−xTi_x and SmFe_12−xV_x were calculated and compared to the available experimental data. This work is supported by the European Research Project NOVAMAG (EU686056) and STandUP for energy (Sweden).