Neutron diffraction study on the magnetic structure of (Fe0.90Cr0.03Ni0.07)2P

Crystal and magnetic structures of (Fe0.90Cr0.03Ni0.07)(2)P have been investigated using neutron powder diffraction measurements over a temperature range of 10-300 K. The system crystallizes in Fe2P type hexagonal structure (P62m space group, Z=3) in which Cr atoms occupy the pyramidal Fell site and Ni atoms occupy the tetrahedral Fe-I site with total preference. Refined values of the cell parameters and atomic positional parameters are quite close to those reported for the parent compound Fe2P. The substituted alloy retains the ferromagnetic order of Fe2P with the moments orienting along [0 0 1] direction. There are signatures of the presence of magnetic clusters. The ordered magnetic moments at 10 K are 0.88(2)mu(B) and 2.16(5)mu(B) at the two metallic sites Fe-1 and Fell, respectively. These values are close to those reported for Fe2P at 77 K. At 297 K, which is in the region of ferromagnetic to paramagnetic transition, the moment at Fe-1 site is quite low at 0.14(3)mu(B) but at Fe-II site, it is still fairly large at 0.67(15)mu(B). (c) 2006 Elsevier B.V. All rights reserved.