Short range order in new rock salt type structures of the system Li$_{3}$NbO$_{4}$-CoO

Abstract

Synthesis of compounds belonging to the system Li$_{3}$NbO$_{4}$-CoO has been obtained by a solid state reaction, the products are appropriately described by the formula Li$_{(3 - 3x)}$Co$_{4x}$Nb$_{(1 - x)}$O$_{4}$; 0 $ \le $ x $ \le $ 1.$_{ }$These new compounds have been studied in their diffraction features. Their electron diffraction patterns are characterized by the existence of a well defined diffuse intensity distribution in addition to sharp Bragg reflections of a rock salt type structure. This has been attributed to the presence of atomic short range order in the structure. As the amount of Co$^{2 + }$ ions increases in the structure, the amount of grains which produces diffuse scattering becomes larger therefore, we propose that the presence of Co$^{2 + }$ drives local spatial cation distribution which would rise electron diffuse scattering. An explanation, in terms of a modulated structure, has been put in advance depicting a probable atomic arrangement to explain the detected short range order.