Elevated temperature deformation of fine-grained La_0.9Sr_0.1MnO₃

Compressive creep behavior of fine-grained (5 μm) La0.9Sr0.1MnO3with a relative theoretical density between 85 and 90% was investigated over the temperature range 1150–1300 °C in air. The fine grain size, brief creep transients, stress exponent close to unity, and absence of deformation-induced dislocations, suggested that the deformation was controlled by a diffusional creep mechanism. The activation energy for creep of La0.9Sr0.1MnO3was 490 kJ/mole. A comparison of the activation energy for creep of La0.9Sr0.1MnO3with existing diffusion and creep data for perovskite oxides suggested that the diffusional creep of La0.9Sr0.1MnO3was controlled by lattice diffusion of the cations, either lanthanum or manganese.