Synthesis and structural characterization of (Bi2O3)1-x (Y2O3)x and (Bi2O3)1-x (Gd2O3)x solid solutions

Solid solution series, (Bi2O3)(1-x) (Y2O3)(x) and (Bi2O3)(1-x) (Gd2O3)(x), for x = 0.10, 0.20, 0.30 and 0.40 were synthesized by standard ceramic technique. The structural phase characterization was carried out using X-ray powder diffraction technique. It was found that the solid solution containing 20-40 mole% of Y2O3 had face-centred cubic structure. All samples of the solid solution series, (Bi2O3)(1-x) (Gd2O3)(x), had rhombohedral single phase in the concentration range 0.10 less than or equal to x less than or equal to 0.40. Lattice parameters of fcc phase of Y2O3 doped samples were calculated from the X-ray diffraction data. The lattice constant 'a' gradually decreases with increasing content of dopant concentration (x) for the Y2O3 doped system and obeys Vegard's rule. The unit cell parameters for the (Bi2O3)(1-x) (Gd2O3)(x) doped samples showing rhombohedral phase were obtained on hexagonal setting.