MAGNETIZATION PROCESS AND MICROSTRUCTURE IN THE FE73.5CU1NB3SI13.5B9 ALLOY

The magnetic properties, i.e. hysteresis loops, coercivity, law of app roach to ferromagnetic saturation and the microstructure of the Fe73.5 Cu1Nb3Si13.5B9 alloy in the as-quenched state and after annealing are investigated. A decrease of the coercivity after annealing the samples in the temperature range from 570 to 830 K is observed. The temperatu re dependence of the Mossbauer spectrum for the crystallized sample re veals two different magnetic phases: Fe3Si grains and the low magnetic matrix. In the magnetic field range 0.02 to 0.1 T the 1/mu0H law is f ulfilled for the samples in the as-quenched state and after annealing at 830 K. A transition from a 1/mu0H law to a 1/(mu0H)2 law for the sa mples annealed at 570 and 740 K takes place. This behaviour is attribu ted to the relaxation process and phase segregation.