Optical and mechanical properties of Li2Mg2(MoO4)3 crystal grown by Czochralski method

Abstract

A Li2Mg2(MoO4)3 crystal was grown by self-flux Czochralski method in a platinum crucible. The polycrystalline compound was synthesised using standard solid-state reaction method. The purity of the synthesised compound was analysed through powder X-ray diffraction method. Single crystal growth was carried out using a Czochralski chamber in argon atmosphere and the pulling rate was maintained 0.5 mm/h with a rotation rate of 8−10 rpm. The temperature dependent luminescence and decay time measurements were carried out in a temperature range of 10–300 K. The grown crystal sample exhibits an intrinsic emission band in a wavelength range from 320 to 800 nm with the maximum peak at 590 nm. At low temperatures, a significant increase in emission intensity is observed as well as the red shift in the peak position. The luminescence decay time was fitted with three decay components. Thermally stimulated luminescence glow curve was recorded to study the trap centers and found a trap center at 25 K with 3 meV trap depth. Mechanical behaviour of the grown crystal was analysed by using Vicker’s micro hardness testing. The results suggest that Li2Mg2(MoO4)3 crystal can be used for luminescence applications.