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

Compressive creep behavior of fine-grained (5 μm) La_0.9Sr_0.1MnO₃with 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 La_0.9Sr_0.1MnO₃was 490 kJ/mole. A comparison of the activation energy for creep of La_0.9Sr_0.1MnO₃with existing diffusion and creep data for perovskite oxides suggested that the diffusional creep of La_0.9Sr_0.1MnO₃was controlled by lattice diffusion of the cations, either lanthanum or manganese.