ANOMALOUS TEMPERATURE-DEPENDENCE OF MAGNETIZATION IN POLYCRYSTALLINE FE65NI35 ALLOY

Magnetization at 0. 3 and 140 Hz (0-10 Oe) and magnetic relaxation measurements were carried out in detail in the temperature range between 4. 2 and 300 K for a polycrystalline Fe//6//5Ni//3//5 alloy. The typical temperature T//g and the magnetic field H//g which correspond to the anomalous temperature in chi -T curves and inflection field in sigma -H curves, respectively, are summarized and a H-T diagram is obtained. A strong magnetic relaxation is observed along the H//g-T line. The temperature dependence of H//g is discussed by the thermal activation of 180 degree domain wall which is pinned strongly by the antiferromagnetic-like clusters below T//g. It is find that Hg** one-half is a linear function of T**2**/**3.