Thermal, anisotropic microhardness and laser induced surface damage studies on certain metal complexes of thiourea

Abstract

Single crystals of thiourea metal complexes with selected group II metal ions, zinc and cadmium, have been grown by solvent evaporation technique and characterized by XRD studies. The thermal, mechanical and laser induced surface damage properties of thiourea and its metal complexes in (1 0 0) plane were studied. From the improved photopyroelectric technique the thermal properties of the metal complexes were evaluated. Due to larger heat capacity ZTS (382.4 J kg −1 K −1) has better thermal stability than BTCC (304.09 J kg −1 K −1), TTCS (293.5 J kg −1 K −1) and BTZC (255.24 J kg −1 K −1). Vickers hardness studies reveal that the materials have reverse indentation size effect and belong to soft material type. Elastic stiffness was found to be very large for ZTS (8.05) than TTCS (5.38), BTCC (1.57 GPa) and BTZC (0.76 GPa). Multi-shot laser damage studies reveal that ZTS (40 GW/cm 2) has higher laser damage threshold and the roles of the group II metal ions in improving the mechanical and thermal stability of the metal complexes are discussed.