The influence of the ultraviolet illumination on the switching processes in barium titanate

We present results of photoconductivity investigation and effect of illumination on switching properties of such materials as bulk grown single crystals of BaTiO3, single crystals of solid solutions on the base of BaTiO3 and barium titanate ceramics. It is found that photoconductivity of ultra-clean ceramics and bulk grown single crystals of BaTiO3 is considerably higher than that of single crystals which were grown from the solution in the melt of KF. These are the materials that when illuminated exhibit the greatest effect of change of the polarization and decrease of the Curie point. A nonisovalent substitution of titanium ions by ions of lower valency was found to cause a negative photoeffect.