Orbital ordering and the dilute effect in copper fluoride

We have investigated the dilute effect on a typical orbital ordering system KCuF3 by partially substituting Zn for Cu. The crystal structure has been examined as a function of Cu concentration at room temperature by X-ray diffraction. It is found that the phase transition from a tetragonal structure to a cubic one occurs with decreasing Cu concentration. This structural phase transition is confirmed to be an orbital order-disorder transition by the resonant X-ray scattering (RXS) technique. (c) 2006 Elsevier B.V. All rights reserved.