Observation of Orbital Ordering in K₂CuF₄

Abstract

Direct observation of orbital ordering in the ferromagnet K 2 CuF 4 has been made by means of the polarized neutron diffraction technique. The observed interference terms between the aspherical contribution of the spin density distribution and the nuclear contribution from the displaced F - ions have been satisfactorily explained in terms of the orbital ordering model proposed by Khomskii and Kugel.