Structural and magnetic properties of LaFe0.5Cr0.5O3 studied by neutron diffraction, electron diffraction and magnetometry

The structural and magnetic properties of the perovskite type compound LaFe0.5Cr0.5O3 have been studied by temperature dependent neutron powder diffraction and magnetization measurements. Rietveld refinement of the neutron diffraction data shows that the compound crystallizes in an orthorhombic perovskite structure with a random positioning of the Fe and Cr cations at the B sublattice. The magnetic structure at 10 K is a collinear antiferromagnetic one with the magnetic moment per site being equal to 2.79(4) mu(B). Magnetisation measurements confirm the overall antiferromagnetic behaviour. Moreover, it indicates a weak uncompensated magnetic moment close to the transition temperature T-N approximate to 265 K. This moment can be described by a magnetic cluster state, which remains up to 550 K. Electron diffraction patterns along with high-resolution transmission electron microscopy images reveal that the crystallites are composed by domains of different orientation, which share the same cubic perovskite sub-cell reflections. (C) 2005 Elsevier Ltd. All rights reserved