Dislocation structures at [001] low-angle grain boundaries in SrTiO₃

Abstract

A dislocation in crystalline materials has dangling bonds at its core and strong strain field in its vicinity. Therefore, it has a potential to exhibit unusual physical properties. In this study, we investigated atomic structure and electric properties of dislocations in strontium titanate (SrTiO₃). In order to introduce dislocations in SrTiO₃, we fabricated a bicrystal with (001) low-angle grain boundaries by a diffusion bonding technique. TEM and STEM observations showed that a (001) low-angle tilt grain boundary mainly consists of [001] dislocations. This is consistent with the past reports. Then we carried out electrical measurement along dislocations at the boundary. It is suggested that electric conductivity along dislocations is different from that in bulk.