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

Spontaneous polarization reversal and domain structures of flux-grown ferro electric KTiOPO4 and isomorphic crystals were studied. Two temperature regi ons with dominant. either ionic or electronic conductivity were found. It w as shown that in the high-temperature region mobile cations contributed suf ficiently to internal screening process. The ionic leakage current was supp ressed at a specific temperature point for each studied crystal. High cryst allographic 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 dom ain configurations used in nonlinear optical conversions.