Relation between lattice parameters and valence state of Cu ions of MxNd 2− xCuO 4− y ( M = Na and Ce) solid solution

Abstract

The lattice parameters, the oxygen content, and the electrical and magnetic properties of M x Nd 2− x CuO 4− y ( M = Na and Ce) with the Nd 2CuO 4 structure have been determined by means of X-ray powder diffraction, thermogravimetry, electrical resistivity, and magnetic susceptibility measurements. The oxidation states of Cu were estimated from the measured y values and the nominal composition x, on the basis of charge neutrality. The composition dependence of the lattice parameters is discussed by taking the oxygen content, the ionic radii, and ( Cu + Cu ) into consideration. The formation of holes and electrons on the CuO bond within the basal plane is discussed in terms of the CuO bond length in the structure of the host materials.