Polycrystalline samples of Eu2-xCexCuO4, where x was between 0 and 0.18, were prepared by using a sol-gel precursor and sintering at 150 to 950C. The results of X-ray powder diffraction studies revealed that complete diffusion of Ce into the matrix occurred in samples that had been sintered at 950C (below the eutectic temperature). It was also observed that Ce diffusion increased monotonically with increasing x-value; thus suggesting that the system was a true chemical solid solution. The solubility limit of Ce in the series was found to be close to an x-value of 0.15. An accurate analysis of the full-width at half-maximum of the X-ray diffraction peaks revealed the presence of an inhomogeneous Ce distribution in samples that had been sintered for short times. An improvement in the homogeneity of the Ce distribution was observed in samples that had been sintered for longer times. The results of differential thermal analysis and thermogravimetry were found to be in complete agreement with the X-ray diffraction data.

P.A.Suzuki, R.F.Jardim: Physica C, 1996, 267[1-2], 153-60