Electrical and nonlinear optical properties of KTiOPO4 single crystals doped by Nb or Sb

Single crystals of K1−xTi1−xNbxOPO4 and K1−xTi1−xSbxOPO4 solid solutions are grown and their dielectric properties, electrical conductivity, and nonlinear optical properties are studied. Maximal content of these dopants x is found to be 0.11 for Nb and 0.23 for Sb. This doping leads to the creation of the additional potassium vacancies and the high ionic conductivity σ33. Ferroelectric phase transitions become more diffuse and their temperature decreases. All the crystals show intensive broad maxima of the dielectric permeability attributed with the relaxation phenomena.