Mechanisms of Thermal Expansion and Shrinkage of La[sub 0.8]Sr[sub 0.2]MnO[sub 3+δ] Perovskites with Different Densities during Thermal Cycling in Air

Abstract

The mechanisms of thermal expansion and shrinkage for sintered La0.8Sr0.2MnO3+δ samples, with different relative densities, have been investigated in air during thermal cycle measurements between 50 and 1100°C. The perovskite samples showed a large thermal expansion coefficient (TEC) at approximately 42°C due to a change from monoclinic and hexagonal phases to a single hexagonal one. The TEC of the porous samples with initial relative densities