ELEVATED-TEMPERATURE DEFORMATION OF FINE-GRAINED LA0.9SR0.1MNO3

Compressive creep behavior of fine-grained (5 mu m) La0.9Sr0.1MnO3 wit h a relative theoretical density between 85 and 90% was investigated o ver the temperature range 1150-1300 degrees C in air. The fine grain s ize, brief creep transients, stress exponent close to unity, and absen ce of deformation-induced dislocations, suggested that the deformation was controlled by a diffusional creep mechanism. The activation energ y for creep of La0.9Sr0.1MnO3 was 490 kJ/mole. A comparison of the act ivation energy for creep of La0.9Sr0.1MnO3 with existing diffusion and creep data for perovskite oxides suggested that the diffusional creep of La0.9Sr0.1MnO3 was controlled by lattice diffusion of the cations, either lanthanum or manganese.