STRUCTURAL STUDY AND MAGNETIC MEASUREMENTS OF SOME PEROVSKITES MLNLITEO6

The crystal structures of the perovskites MLnLiTeO6 (M = Ca, Sr and Ba ) were determined from X-ray diffraction patterns. Rietveld analysis o f the data gave at ambient temperature an ordered distribution of Liand Te6+ formal cations in B sites whereas the M2+ and Ln3+ cations oc cupy the A sites at random. Space groups and lattice parameters of the se oxides are discussed on the basis of the distortions on the ideal p erovskite structure. On the other hand, magnetic measurements are comp atible with this distorted model in which paramagnetic cations are iso lated.