MAGNETIC-PROPERTIES AND CRYSTALLIZATION OF AMORPHOUS FE90-XMNXZR10 ALLOYS WITH X=0-15

A systematic investigation of the Curie temperature T-c, magnetic mome nt <(mu)over bar> and spin-glass-like behavior of amorphous Fe90-xMnxZ r10 (x = 0, 4, 6, 10 and 15) has been performed by magnetization measu rements, The magnetic moment and the Curie temperature of amorphous Fe -Mn-2r alloys are found to decrease monotonically with increasing Mn c oncentration. The decrease of <(mu)over bar> and T-c with x may be due to the antiparallel coupling between the Fe and Mn atoms. It is found that there is a transition of ferromagnetic to spin-glass phase at lo w temperature. The spin freezing temperature T-f is found to increase with increasing Mn concentration from about 32 K for x=0 to about 62 K : for x = 15. The thermomagnetic curves measured at heating and coolin g temperature on the sample crystallized from amorphous Fe84Mn6Zr10 al loy show an irreversible magnetic transition. This anomalous phenomeno n can be attributed to the transition of the ferromagnetic alpha-(Fe,M n) phase to the nonmagnetic gamma-(Fe,Mn) phase for heating at about 1 000 K and from gamma-(Fe,Mn) phase to alpha-(Fe,Mn) phase for cooling at about 570 K. (C) 1997 Elsevier Science S.A.