Study of Phase Purity of Eu<sub>2-x</sub>Ce<sub>x</sub>CuO<sub>4</sub> Synthesized by Solid State Method without Annealing Process

Abstract

The samples of Eu2-xCexCuO4 (ECCO) with x = 0.10, 0.13, 0.17 and 0.20 have been synthesized by the solid reaction method without annealing process [1,2]. Each sample is covered by CuO powder to prevent excess oxygen entering the sample during heating process. The purpose of this research is to study the crystal structure and the level of phase purity in ECCO samples in the wide ranges of doping concentration of ECCO. The results of X-ray diffraction (XRD) characterization showed that the main peaks of T' tetragonal structure were observed in all samples. From the XRD analysis, it was found that the level of phase purity of ECCO was 100 % for x = 0.10, 100 % for x = 0.13, 79.5.% for x = 0.17, and 79.1 % for x = 0.20, respectively. For the lattice constant, it is found that both a and c-axis did not change significantly as the concentration increased. These results show that the synthesis method with CuO covering has succeeded in synthesizing materials with high phase purity although the constants do not change significantly when the concentration increased. However, there are some impurity phases found in high concentration of x that is probably due to the existence of excess oxygen, which was not fully absorbed by CuO Covering.