SPIN-WAVE STIFFNESS CONSTANT OF AMORPHOUS (CO1-XNIX)75SI10B15 ALLOYS

We report here the spin wave stiffness constants of amorphous (Co1-xNi x)75Si10B15 (0.1 less-than-or-equal-to x less-than-or-equal-to 0.5, x increases in steps of 0.1) alloys obtained from the low temperature ma gnetization curves and spectroscopic splitting g factors. The low temp erature dependence of the magnetization was measured with a supercondu cting quantum interference device magnetometer and the g values were d erived from ferromagnetic resonance measurements. The g values increas e with increasing Ni content. The temperature dependence of magnetizat ion is in good agreement with Bloch's relation M(s)(T) = M(s)(0)(1 - B T3/2 - CT5/2) at low temperatures, and the spin wave stiffness constan ts become smaller with the addition of Ni.