Quasi-two-dimensional d-spin and p-hole ordering in the three-dimensional perovskite La1/3Sr2/3FeO3

Abstract

Measurements of resonant soft x-ray magnetic scattering reveal anomalous ordering of 3d spins and 2p holes in perovskite La1/3Sr2/3FeO3, which is known to exhibit three-dimensional (3D) charge and spin ordering along the (111) direction. Upon cooling, a quasi-two-dimensional phase consisting of ferromagnetic and charge-disproportionated [111] trilayers of Fe3+-Fe5+-Fe3+ precedes the development of 3D magnetic ordering at the transition temperature, in sharp contrast to an ordinary transition from the paramagnetic and charge-uniform phase to the antiferromagnetic and charge-disproportionated phase expected according to conventional wisdom.