OXIDATION-KINETICS OF POLYCRYSTALLINE LACRO3

The oxidation kinetics of polycrystalline LaCrO//3 were determined by measuring the time and temperature dependence of the weight and conductivity change of reduced samples. A region of fast diffusion followed by a smaller, slower diffusion 'tail' was observed in the thermogravimetric measurements. This observation can be interpreted as the rapid diffusion along the grain boundaries and subsequent diffusion into the body of the grain. The absence of the 'tail' in the conductivity measurements is due to the high hole mobility along the boundaries.