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Abstract: Large crystals of Hg2Cl2 and Hg2Br2 (48mm in diameter, up to 600g in weight) have been grown by the physical vapor transport (PVT) technique in closed ampoules in vertical configuration without contact with the ampoule walls. The starting materials have been pre-purified by resublimation. Seed selection has been accomplished by having a narrow tubing at the tip of the growth ampoule. Thermochemical analysis of the system is done and discussed. The grown crystals show good transparency and good crystallographic quality. An acousto-optic modulator built from the Hg2Cl2 crystal showed good performance consistent with predicted device parameters. [Copyright &y& Elsevier]

Single crystals of mercurous halide were grown by physical vapor transport method (PVT). The orientation and the crystalline quality of the grown crystals were determined using high resolution x-ray diffraction (HRXRD) technique. The full width at half maximum (FWHM) of the grown mercurous bromide crystals was measured to be 0.13 degrees for (004) reflection, which is the best that has been achieved so far for PVT grown mercurous halide single crystals. The extended defects of the crystals were also analyzed using high resolution x-ray diffraction topography. Preliminary studies were carried out to evaluate the performance of the crystals on acousto-optic modulator (AOM) and gamma-ray detector applications. The results indicate the grown mercurous halide crystals are excellent materials for acousto-optic modulator device fabrication. The diffraction efficiencies of the fabricated AOM device with 1152 and 1523 nm wavelength lasers polarizing parallel to the acoustic wave were found to be 35% and 28%, respectively. The results also indicate the grown crystals are a promising material for gamma-ray detector application with a very high energy resolution of 1.86% FWHM. [ABSTRACT FROM AUTHOR]