V alloys*

We have investigated the structural and magnetic properties of melt-spun Co_3+xV alloys for x = 0, 0.2, 0.4 and 0.6 in order to study the effect of structural disorder on the magnetic properties of Co-V alloys. Bulk Co₃V exists in two phases: An ordered hexagonal (Al₃Pu-type) low-temperature phase (LTP) and a cubic L1₂ (Cu₃Au)-type high-temperature phase (HTP) [1, 2]. Both the LTP and HTP are paramagnetic down to 4.2 K. The as-spun samples have the HTP structure. However, when they are annealed at 1173 K, they transform into the LTP. Magnetic data suggest that the as-made ribbons are ferromagnetic with ordering temperatures of 10, 20, 30 and 75 K for x = 0, 0.2, 0.4 and 0.6, respectively. This behavior is attributed to a slight destruction of perfect order in the HTP and which can lead to an increase in the Co-Co exchange interaction. The magnetic properties of annealed samples are currently being measured and the results will be presented and discussed at the meeting.

[1] Y. Aoki, K. Asami, and M. Yamamoto, Phys. Stat. Sol. (a) 23, 167 (1974).
[2] Y. Aoki and M. Yamamoto, Phys. Stat. Sol. (a) 33, 625 (1976).