Top-Seeded Solution Growth and Properties of K_1–xNa_xNbO₃ Crystals

Abstract

A series of large-sized (maximum 16 × 16 × 20 mm 3 ), high-quality K 1−x Na x NbO 3 (x = 0.118, 0.378, 0.462, 0.545, and 0.666) single crystals were successfully cultivated using the top-seeded solution growth method. The crystallization and structures of the K 1−x Na x NbO 3 single crystals were studied using first-principles calculations and X-ray diffraction, respectively. The segregation of the K 1−x Na x NbO 3 single crystals was investigated, which enabled precise control of the individual components of the crystals during growth. Excellent properties were obtained without annealing, including a low dielectric loss (minimum 0.2%), a saturated hysteresis loop with a low coercive field E c , a large piezoelectric coefficient d 33 (d 33 = 161 pC/N when x = 0.378), and a low leakage current density J (10 −6 A/cm 2 ). These results indicated that the K 1−x Na x NbO 3 (x = 0.118, 0.378, 0.462, 0.545, and 0.666) crystals can be used as a high-quality, lead-free piezoelectric material.

Origin of giant piezoelectric effect in lead-free K1−xNaxTa1−yNbyO3 single crystals

“…The quality of K 0.39 Na 0.61 Ta 0.42 Nb 0.58 O 3 was better than the other two components crystals as its tan δ was the smallest. Furthermore, it was similar or smaller than that of the crystals reported previously in the literature 26 29 .…”

“…Concomitantly, the value of T C decreased from 228 °C to 161 °C. According to the data of pure KNN single crystals 26 , we can determine that the value of T O-T and T C of the KNN crystals slightly increased with decrease of Na concentration. However, the T C of KTN single crystals gotten by the function T C = 676 x + 32 K ( x is the Nb concentration in KTN crystals) 27 decreased with doping Ta.…”

Dielectric, piezoelectric, and elastic properties of K0.8Na0.2NbO3 single crystals

“…20 According to the Institute of Electrical and Electronics Engineers (IEEE) standards, 21 We used combined resonance-antiresonance and ultrasonic methods, together with capacitance measurements, to obtain the 11 independent constants, which allowed us to determine these coefficients with a high degree of self-consistency. High-purity (99.99%) K 2 CO 3 , Na 2 CO 3 , and Nb 2 O 5 powders were used as the raw materials and were weighed to obtain a composition of K 0.8 Na 0.2 NbO 3 ; excess Na 2 CO 3 and K 2 CO 3 were added as a self-flux.…”

Optical Properties of the Fresnoite Ba2TiSi2O8 Single Crystal

“…In particular, the existence of nonlinear absorption may decrease the frequency conversion efficiency, and may even result in internal damage when optical devices are used in a high-power laser system. Therefore, a better understanding of optical properties of crystalline material [16][17][18], especially the nonlinear absorption properties of the BTS crystal, is essential to realize its optical applications.…”