Growth of Ferroelectric Tri-Glycine Sulphate Doped Potassium Dihydrogen Phosphate Single Crystal and Its Characterization

Abstract

Potassium dihydrogen phosphate (KH2PO4, KDP) single crystals have been long studied due to their non-linear optical property. Also, these crystals can exhibit some ferroelectricity when applying an external electric field. In the absence of the external field, the remaining polarization is weak, and hence, the applications of KDP in the electronic industry are limited. In order to enhance the ferroelectricity of the KDP crystals, tri-glycine sulphate (TGS) was added to the KDP solution and then the doped crystals were grown using the slow evaporation method. The results show that the properties of TGS doped KDP crystals are similar to those of the pure KDP. However, the ferroelectricity of the TGS doped KDP has been improved by the small addition of the TGS. These reveal that the TGS molecules may disrupt the KDP lattice and hence, lead to the enhancement of the built-in polarization.