Thermal expansion behavior and polarization properties of lead-free ferroelectric potassium lithium tantalate niobate single crystals

Lead-free ferroelectric niobium-rich potassium lithium tantalate niobate K0.95Li0.05Ta1−xNbxO3 (KLTN) single crystals were grown by the top-seeded melt method. Thermal expansion properties of K0.95Li0.05Ta1−xNbxO3 (x=0.78, 0.69, 0.60, and 0.52) single crystals were investigated in the temperature range of 140 K–800 K using a dilatometer. According to the thermal expansion data, phase transition temperatures of all compositions were determined, and temperature dependence of local polarization was calculated. In addition, the results were discussed in combination with the composition and crystallographic orientation.