Noncentrosymmetric Orthophosphate YM₃(PO₄)₃ (M = Sr, Ba) Crystals: Single Crystal Growth, Structure, and Properties

Abstract

Two noncentrosymmetric orthophosphate crystals, YSr3(PO4)3 and YBa3(PO4)3, with melting points over 1800 °C have been grown by using the Czochralski technique. The YSr3(PO4)3 and YBa3(PO4)3 crystals were determined to possess cubic symmetry with a space group of I4̅3d. The cell parameters were determined tobe a = b = c = 10.081(9) Å, V = 1024.6(3) Å3, and Z = 4 for YSr3(PO4)3; and a = b = c = 10.452(2) Å, V = 1141.9(7) Å3, and Z = 4 for YBa3(PO4)3 crystal. Both the YSr3(PO4)3 and YBa3(PO4)3 crystals were found to show disordered occupations between Sr (or Ba) and Y. Thermal properties were also characterized, where the thermal conductivity values were 1.53 W·m–1·K–1 and 1.39 W·m–1·K–1. The YSr3(PO4)3 and YBa3(PO4)3 crystals were confirmed to possess a broad transmittance range with an optical absorption edge shorter than 190 nm. In addition, the laser-damage thresholds of YSr3(PO4)3 and YBa3(PO4)3 crystals were evaluated at wavelengths of 1064 nm using a 10 ns Nd:YAG laser and found to be on the order of 1150 MW/cm2 and 680 MW/cm2, respectively. The YSr3(PO4)3 and YBa3(PO4)3 single crystals were shown to be good multifunctional crystals for potential opto-electric applications.