Investigations on synthesis, growth and physical characterization of lithium selenoindate single crystals

• Melt and temperature oscillation method was adopted for synthesizing LiInSe2
• The large LiInSe2 crystal of high integrity was grown by the modified vertical-Bridgman–Stockbarger method.
• RBS measurement confirms the composition of the LiInSe2
• PSR model is applied for hardness measurements.

Crack free LiInSe2 single crystal with bottom dimension of 8 mm diameter and 10 mm length and top dimension of 12 mm diameter and 22 mm length was grown using modified vertical Bridgman–Stockbarger method with steady ampoule rotation. The grown LiInSe2 crystal was characterized by X-ray diffraction pattern, Rutherford backscattering spectroscopy (RBS) analysis, Thermogravimetric-Differential thermal (TG-DTA) analysis, optical transmission and microhardness measurements. X-ray diffraction pattern gives the orientation of the crystal as 〈002〉. RBS analysis confirms that the composition of the grown crystal is Li0.8In1.16Se2.04. TG-DTA analysis confirms that the melting point of the grown crystal is 897.5 °C. Optical behavior has been assessed by ultraviolet–visible–near infrared spectroscopy and Fourier transform infrared analysis. LiInSe2 optical band gap energy is 2.72 eV and the cut off wavelength is 450 nm. Mechanical behavior has been studied using Vickers Microhardness measurements.