We found that the pseudo binary alloys (Mn1-xRux)3Ga, with 0.33 ≤ x ≤ 0.67, have an ordered b.c.c. structure. The lattice constant a is almost constant with respect to x: a = 6.000 Å for x = 0.33 and a = 5.992 Å for x = 0.67. For the alloy with x = 0.33, i.e. Mn2RuGa, the magnetization is almost saturated in a field of 20 kOe. The saturation magnetization at 4.2 K is 23 emu/g, and the Curie temperature, TC, is 460 K. The TC of (Mn1-xRux)3Ga decreases almost linearly with increasing x, and it vanishes around x = 0.67 (MnRu2Ga). We also determined atomic and magnetic structures from neutron diffraction experiments. The alloy Mn2RuGa (x = 0.33) has an ordered structure of CuHg2Ti type; the magnetic Mn atoms mainly occupy the 4a (0,0,0) and 4d (3/4, 3/4, 3/4) sites. We also observed that the magnetic moments of Mn atoms on the 4a and 4d sites are antiparallel to each other; values of the magnetic moment are μa = 4.6 and μd = 3.3 μB per Mn atom.
|ジャーナル||Applied Physics A: Materials Science and Processing|
|出版ステータス||Published - 2002 12月 1|
ASJC Scopus subject areas
- 化学 (全般)