Tl3PbBr5: A possible crystal candidate for middle infrared nonlinear optics

Centimeter-sized single crystals of Tl3PbBr5 were successfully grown using the Bridgman–Stockbarger method. We present the growth conditions together with a characterization of the single crystals by means of DSC measurements, room and high-temperature X-ray powder diffraction, scanning electron microscopy and EDX analysis. An Ellingham diagram for bromides aimed at choosing the crucible material, synthesis and crystal growth atmosphere and starting products is proposed. We also stress the close-to-equilibrium first order character of the phase transition undergone by this compound at 237 °C, as well as the Raman, Fourier-transform infrared, visible spectroscopic basic properties and second harmonic generation tests, suggesting its potential for middle infrared nonlinear optics.