Modified Bridgman growth and characterization of a novel mid-infrared transparent optical crystal: LiGa3Te5

Abstract

A large single LiGa₃Te₅ (LGT) crystal was grown with size up to Ø16 mm × 50 mm for the first time using a modified vertical Bridgman–Stockbarger method. LGT crystallizes in the non-centrosymmetric system, space group R32, with a = b = 14.343(7) Å, c = 17.617 Å, Z = 12, and V = 3139 ų. A detailed description of the polyhedral connections in the LGT structure is presented. The X-ray rocking curve, specific heat and thermal conductivity are also investigated. The room-temperature transmission of the as-grown LGT without any coating is above the 40% level from 3.5 to 18 μm. The cut-off edges at short and long wavelength are 0.9 and 25 μm, respectively. Owing to its wide transparency range, LGT is a promising candidate for MIR and far-infrared NLO applications, and even for THz transmission and generation.