Investigation on the structural, linear/nonlinear optical and electrical characteristics of Cd- and Mn-doped polar lithium sulfate monohydrate crystals

Abstract

Bulk size pyroelectric undoped and Cd- and Mn-doped lithium sulfate monohydrate (LSMH) single crystals were successfully grown along the polar axis by the unidirectional crystal growth method. The influence of transition metal ions (Cd and Mn) on crystal growth and the linear/nonlinear optical, pyroelectric, and piezoelectric properties of the LSMH crystal were studied. The crystalline perfection of the grown crystals was assessed using a rocking curve of the HRXRD pattern. The vibrational spectroscopic properties of undoped and doped single crystals were analyzed using micro-Raman scattering measurements on the 〈010〉-oriented crystal surface. The optical quality was assessed by recording the UV-Vis-NIR transmission on the different sectors of the crystal. The refractive index at five different wavelengths in the range of 407–1551 nm and birefringence properties of Cd- and Mn-doped crystals were analyzed using the prism coupling method. The second harmonic generation capability of the material was studied using the Kurtz and Perry technique. The pyroelectric coefficients of these crystals were determined by measuring the pyroelectric current as a function of temperature. Piezoelectric studies were carried out on the (010) surface of the undoped and doped samples. The LSMH crystals grown from a solution containing Mn ions were found to have a satisfactory second harmonic generation capability and piezoelectric coefficient.