Magnetocrystalline Anisotropy Measured on Y2+xCo17−2x Single Crystals

Magnetic properties of hexagonal Y2+xCo17−2x single crystals with 0.23≥x≥−0.073, in which paired Co atoms are disorderly substituted by Y atoms in proportion to x, have been studied over a temperature range from 77 to 575 K . Saturation magnetization and Curie temperature decrease monotonically with increasing x. The magnetocrystalline anisotropy constant K1 calculated from magnetization data changes its sign from negative to positive at small x at all the temperatures studied, for example, at x=0.115 at 77 K . The local anisotropy constant of the paired Co atom is estimated from the variation of K1 with x and found to be −1720 m−1/Co at 77 K . Anisotropic behavior of Co in each crystallographic site in 2–17 type alloys is discussed on the basis of the experimental data.