Temperature-dependent elastic, mechanical, thermal, and acoustic behavior in alkaline earth semiconductors

Abstract

This study investigates the temperature-dependent elastic, mechanical, thermal, and acoustic features of alkaline earth semiconductors calcium monochalcogenides CaX (X = S, Se, Te). First of all, the second- and third-order elastic constants have been calculated in the temperature range 0–500 K using the Born-potential model. The evaluated SOECs values were utilized to compute the mechanical constants at 0 K and 300 K. Selected materials in the present investigation have been found mechanically stable and brittle, in nature. The elastic anisotropy of the mechanical moduli has been presented using the 3D surface. SOECs have also been employed to perceive the acoustical wave velocities for longitudinal and shear modes of propagation and Debye mean velocities along <100>, <110>, and <111> directions. SOECs and TOECs were used to calculate the acoustic Grüneisen parameters. Further, the Debye characteristic temperature, thermal conductivity, specific heat, and energy density were computed for CaX. Finally, the direction-dependent ultrasonic attenuation due to phonon–phonon interaction and thermelastic relaxation process has been computed for CaX at room temperature. The results obtained have been validated with existing results that are accessible for the chosen materials.