Magnetocrystalline Anisotropy in Y(Co sub 0.85 Al sub 01.5 ) sub 2 With the C15 Cubic Laves Phase Structure

The temperature dependence of the first magnetocrystalline anisotropy constant K sub 1 has been deduced from the analysis of isothermal magetization curves I(H) for polycrystalline Y(Co sub 0.85 Al sub 0.15 ) sub 2 samples with the C15 cubic laves phase structure. The magnitude of K sub 1 is equal to 7.6 x 10 exp 4 erg cm exp --3 at T = 7K and falls rapidly with increasing temperature. K sub 1 has a negative sign over the temperature range investigated from 7-20K, i.e. below T sub C = 25K. The results of the anisotropy study are used to explain the low-field magnetic behavior of the Y(Co sub 0.85 Al sub 0.15 ) sub 2 alloy.