STRUCTURE, MICROSTRUCTURE AND TRANSPORT PROPERTIES OF MIXED CONDUCTING LANTHANUM GALLATE BASED PEROVSKITE CERAMICS

摘要

Structure, microstructure, dielectric and transport properties of ceramics (La0.9Sr0.1)[(Gal-xMx)0.8Mg0.2]Oy with M=Fe, Ni, Mn have been studied. Substitution of Fe, Ni, Mn for gallium leads to the perovskite lattice contraction at low concentrations of the transition elements, while to the increasing in the unit cell volume due to the transition element valence changing at higher concentrations. For all the systems studied transformation from pure ionic to the mixed ionic-electronic conductivity is observed at increasing the transition ions content. Concentration dielectric-metal transitions have been revealed in the Mn-containing system, magnetic phase transitions have been observed in compositions with x=0.8 and 1.0 at low temperatures.