Solid solubility of neodymium in BaCeO{sub 3}

Incorporation of Nd into the BaCeO{sub 3} perovskite structure was studied by quantitative wavelength dispersive spectroscopy-electron probe microanalysis (WDS/EPMA) in combination with scanning electron microscopy (SEM) and X-ray powder diffractometry (XRPD). Highly Nd-doped BaCeO{sub 3} specimens, synthesized by mixed oxide technology, were sintered at 1,400 C in ambient air. Concentrations of cations obtained by microanalysis were calculated to the ABO{sub 3} perovskite formula, considering incorporation of Nd at Ba as well as at Ce sites. Nd-BaCeO{sub 3} solid solutions may be represented by the general formula Ba{sub 1{minus}X}Nd{sub X}Ce{sub 1{minus}Y}-Nd{sub Y}O{sub 3{minus}(Y{minus}X)/2}(V{sup {sm_bullet}{sm_bullet}}{sub O}){sub (Y{minus}X)/2}. The ratio between Nd incorporated at Ba sites and at Ce sites (X/Y) is a function of the starting composition, changing from 1 in the CeO{sub 2}-rich part of the BaO-CeO{sub 2}-Nd{sub 2}O{sub 3} system, to {approximately} 0.1 in the BaO-rich part of the system.