LOW-TEMPERATURE MAGNETIC-BEHAVIOR OF AMORPHOUS AND NANOCRYSTALLINE FE73.5CU1NB3SI13.5B9 ALLOYS

The initial susceptibility, virgin magnetization curves, hysteresis lo ops, and saturation magnetization are measured in the temperature rang e from 80 to 290 K for the Fe73.5Cu1Nb3Si13.5B9 alloy in the as-quench ed state and after annealing. It is stated that domain wall movements are dominant magnetization processes in nanocrystalline alloys. The co ercivity distinctly increases after cooling crystallized samples to 80 K. In the temperature range from 80 to 230 K, the saturation magnetiz ation obeys a T3/2 law for all samples. No necessity for introducing a T5/2 term is observed up to 230 K. The spin wave stiffness constant i ncreases with annealing temperature and time.