Magnetism of UFe4-xAl8+x (x = <-0.4, 0.4 >) intermetallics

Results of X-ray, neutron diffraction, magnetization and Mossbauer measurem ents with circularly polarised beam on polycrystalline samples of the terna ry intermetallic alloys UFe4-xAl8+x with x in the range (-0.4, 0.4) are pre sented. The alloys crystallise in the structure of ThMn12 type, belonging t o the space group I4/mmm (no. 139). X-ray and neutron diffraction confirmed the phase homogeneity of all samples but that one with 4-x=4.4. Monochroma tic Circularly Polarised Mossbauer Source (MCPMS) measurements reveal spin- canted magnetic structures in randomly oriented powders exposed to a field of 1 T at T=12 K. Magnetization measurements in an external field of 0.01 T allowed disclosing ferromagnetic-like behaviour vs. temperature and quite dissimilar magnetization and hysteresis curves against the fields in the al loys of interest. (C) 2001 Elsevier Science B.V. All rights reserved.