Oxide ceramics with high density dislocations and their properties

Dislocations are of scientific and technological interest due to their unusual physical properties, which are quite different from those in the bulk. It is, therefore, expected to use dislocations as nanowires which provide functional properties in a crystal. In this study, high densities of dislocations were introduced in oxide single crystals by high-temperature plastic deformation. Insulating sapphire and YSZ single crystal were used as model systems. The electron and ion conductivities were measured for the dislocation introduced crystals respectively. It was found that the dislocations with Ti segregation in sapphire crystal showed excellent electrical conductivity and dislocations themselves in YSZ crystal improved the ionic conductivity. This technique has a potential to be applied for any crystals because of its simplicity, and will be expected to give special and unprecedented properties to common materials.