MAGNETOVOLUME EFFECTS AND MAGNETIC-ANISOTROPY IN CE-3(FEM)(29) COMPOUNDS (M=TI, CR)

The magnetovolume effects and magnetic anisotropy of the new Ce-3(FeTi )(29) and Ce-3(FeCr)(29) compounds have been studied by measuring thei r linear thermal expansion (LTE), pressure dependence of the Curie tem perature T-c, compressibility, and anisotropy field. The value of T-c, its pressure dependence dT(c)/dp, and anisotropy field H-A for the Ce (FeCr)(12) phase are also reported. The linear thermal expansion of th ese compounds exhibits Invar-like behavior with large positive values of the spontaneous magnetostriction at T-c [e.g., omega(s)(0) approxim ate to 1.2% in Ce-3(FeTi)(29)]. Different values of the compressibilit y have been observed in the ferromagnetic and paramagnetic states of C e-3(FeTi)(29) (kappa(f) = 1.25 X 10(-3) kbar(-1) and kappa(p) = 1.12 X 10(-3) kbar(-1)) in qualitative agreement with the large magnetovolum e effect observed in the LTE. T-c for all the phases studied decreases under pressure with initial slopes dT(c)/dp = -3.75, -3.6, and -2.7 K /kbar for Ce-3(FeTi)(29), Ce-3(FeCr)(29), and Ce(FeCr)(12), respective ly. Two anisotropy fields have been detected in Ce-3(FeTi)(29) associa ted with saturation along the b (H-A) and c (H'(A)) axes of the monocl inic structure. The temperature dependence of H'(A) for Ce-3(FeCr)(29) and H-A for Ce(FeCr)(12) is also reported. (C) 1995 American Institut e of Physics.