Polarization reversal and domain anisotropy in flux-grown KTiOPO4 and isomorphic crystals

Abstract

Spontaneous polarization reversal and domain structures of flux-grown ferroelectric KTiOPO4 and isomorphic crystals were studied. Two temperature regions with dominant either ionic or electronic conductivity were found. It was shown that in the high-temperature region mobile cations contributed sufficiently to internal screening process. The ionic leakage current was suppressed at a specific temperature point for each studied crystal. High crystallographic asymmetry of domain wall velocity was observed. This shows that the electrode pattern should be properly oriented relative to the crystal axes of KTiOPO4 and its isomorphs for fabrication of periodically poled domain configurations used in nonlinear optical conversions.