Magnetic properties, phase stability, electronic structure, and spin polarization ratio of L 21 -type phase in Co2 (V1-x Mnx) Ga Heusler alloys have been investigated experimentally and theoretically. The experimental magnetic moments Ms at 4.2 K linearly increase with increasing x, in situ with the generalized Slater-Pauling rule. The experimental Curie temperature TCexpt. exhibits a maximum value of about 704 K at x=0.75. The latter behavior is comparable to the calculated Curie temperature TCcalc. from the theoretical effective exchange constant J0. Although the order-disorder transition temperature Tt L 21 B2 from the L 21 - to B2 -type phase linearly decreases with increasing x, it is relatively high enough in the entire concentration region. The high value of Tt L 21 B2 means that the L 21 -type phase can exist stably, which is very important for practical uses. The calculated density of states by the linear-muffitin orbital method with the atomic sphere approximation disclosed that the spin polarization ratio P of the alloy with x=0.75 is the highest in the present substituted alloys.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2008 Mar 13|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics