STRUCTURAL INSTABILITY AND SUPERCONDUCTIVITY OF THE (Nd, Gd, Ce)2CuO4 SYSTEM

Abstract

The influence of partial substitution of Nd by Gd and Ce on the Nd 2 CuO 4n-type superconductor was studied by using X-ray diffraction measurements. For x = 0.15 Ce the maximum value of critical transition temperature Tc was obtained. The influence of Gd concentration on the lattice parameters and unit-cell volume was studied in the optimal doped sample (x = 0.15 Ce ) and in the samples with 0≤x≤0.2 Ce . The relation between structural parameters and critical transition temperature was evidenced. The transition from the structural normal phase to the distortion phase was evidenced above y = 0.75 Gd in the optimal Ce -doped sample.