Magnetic ordering of ErFe4Ge2 studied by neutron diffraction and magnetic measurements

The magnetic properties of the compound ErFe4Ge2 have been studied by magne tic measurements and neutron diffraction. Magnetic ordering was found to se t in below T-N = 42 K. Magnetic ordering is accompanied by an orthorhombic deformation of the tetragonal lattice, starting at about 35 K. At 8 K there is a further phase transition characterised by a spin-reorientation of the Er moments. The magnetic structure at 1.5 K consists of a canted arrangeme nt with three-dimensional components and two different Er sites. The moment of Er1 equals 5.4(1) mu(B), and makes an angle of 55 degrees(2 degrees) wi th the c-axis, while the moment of Er2 equals 8.5(2) mu(B) and makes an ang le of 42 degrees(2 degrees) with the same axis. The Fe moment ordering disp lays a three-dimensional canting. (C) 1999 Elsevier Science B.V. All rights reserved.