Grain boundary and lattice diffusion of Mn in ATiO/sub 3/ (A=Ba, Sr)

Abstract

The diffusion constant of Mn in polycrystalline BaTiO/sub 3/ and SrTiO/sub 3/ was determined between 1000 degrees C and 1200 degrees C. Its value was found to be more than four orders of magnitude larger than one would expect for volume diffusion of Mn. This result was in accordance with the presence of Mn in the grain-boundary phases. Effective activation energies of 5.9-6.8 eV are estimated.<>