Compressive creep tests of Sr3(Ca1.18Nb1.82)O9−δ mixed perovskite, prepared by melt processing, were performed in Ar and air in order to determine the deformation rate and to estimate the diffusion coefficient. At 1300 to 1350C, the steady-state strain rate could be expressed as:

dε/dt = Aσ1.9 exp[-670(kJ/mol)/RT]

The data and microstructural observations indicated that the mechanism which controlled plasticity was grain-rotation, associated with redistribution of the intercellular phase; accommodated by cell coalescence due to diffusion and dislocations.

Diffusion and Creep of Sr3(Ca1.18Nb1.82)O9−δ Mixed Perovskite Fabricated by Melt Processing. M.J.López-Robledo, A.R.de Arellano-López, J.Martínez-Fernández, A.Sayir: Solid State Ionics, 2007, 178[3-4], 207-11