Accommodation of nonstoichiometry in (100) fiber-textured (BaxSr1−x)Ti1+yO3+z thin films grown by chemical vapor deposition

We have investigated the microstructural accommodation of nonstoichiometry in ${\mathrm{(Ba}}_x{\mathrm{Sr}}_{\text{1−x}}){\mathrm{Ti}}_{\text{1+y}}{\mathrm{O}}_{\text{3+z}}$ thin films grown by chemical vapor deposition. Films with y=0.04 and y=0.15 were studied by high-spatial resolution electron energy-loss spectroscopy, revealing changes in chemistry and local atomic environment both at grain boundaries and within grains as a function of titanium content. We find that excess titanium in the samples with y=0.15 segregates to the grain boundaries in addition to being partially accommodated in the grain interior.