TRANSPORT STUDIES OF THE SOLID-SOLUTIONS X-SRO-X)ND2O3 - -THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-0.15((1)

SrO-doped Nd2O3 systems (SDN) containing 1, 5, 10, and 15 mol% SrO wer e found to be solid solutions by X-ray diffraction (XRD) analysis. The lattice parameters(a) were obtained by the Nelson-Riley method, and t he values increased with increasing dopant content. Thermal analysis s howed that no phase transition occurred in the temperature range cover ed in this experiment. The electrical conductivity increases with temp erature (450-115-degrees-C), but breaks appear in the conductivity cur ve, dividing it into two temperature regions. At the high temperatures of 750-840 to 110-degrees-C, the activation energy (E(a)) and oxygen pressure dependence of conductivity are found experimentally to be ave rage 1.44 eV and 1/n=1/5.3, and the possible defects and charge carrie rs are suggested to be metal vacancies and electron holes, respectivel y. At the lower temperatures of 450 to 750-840-degrees-C, the E(a) and 1/n values obtained are average 0.51 eV and 1/n=1/7.3 to 1/8.3, respe ctively. At the lower temperature, the SDN system may contain a mixed conduction involving ionic conductivity due to diffusion of oxygen ion .