Effect of heterovalent substitutions on the electrical conduction of rubidium diphosphate

Solid solutions were synthesized in the systems Rb4-3xMexP2O7 (Me = Y, La, Nd, Sm, Gd, Yb), and their crystal structure and electrical conduction were studied. A correlation is established between the width of the single-phas e region and the activation energy of the rubidium-cation conductivity, on the one hand, and the size of the modifying cation Me3+, on the other. Elec trical characteristics are compared of solid solutions in the systems Rb4-3 xMexP2O7 and the previously investigated systems Rb4-2xMexP2O7 (Me = Ca, Sr , Ba, Pb). Conclusions are made concerning the main factors determining the transport properties of solid electrolytes based on rubidium diphosphate.