Quasi-two-dimensional d-spin and p-hole ordering in the three-dimensional perovskite La(1/3)Sr(2/3)FeO(3)

Abstract

Measurements of resonant soft x-ray magnetic scattering reveal anomalous ordering of 3d spins and 2p holes in perovskite La(1/3)Sr(2/3)FeO(3), 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 Fe(3+)-Fe(5+)-Fe(3+) 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.