Optimized Growth of Large-Sized LiInSe2 Crystals and the Electric-Elastic Properties

Single crystals of an environmental friendly material LiInSe2 (LISe) with dimensions up to Phi 16 mm X 55 mm were grown successfully through a modified vertical Bridgman technique. The quality of the crystal was measured by a high resolution X-ray diffraction rocking curve, and a full width at half-maximum (fwhm) for a, b, and c faces are 47 '', 46 '', 36 '', respectively. It indicates that the as-grown crystal is high quality. The complete sets of dielectric, elastic, and piezoelectric constants of LISe crystals at room temperature were obtained by the resonant technique and impedance analysis for the first time. The piezoelectric constants d(24) and d(33) reached -13.6 pC/N and 8.5 pC/N, respectively. The corresponding electromechanical coupling Coefficient k(33) is 21%. In addition, the structural distortions and dipole moments of LISe were analyzed in detail. Our results show that LISe is a promising candidate as an environmental friendly piezoelectric material.