Paper Title
Study of Microhardness and its Related Physical Constants of BTZA and L-Cystiene Doped BTZA Single Crystals

Abstract
Single crystals of BTZA and L BTZA were grown by slow evaporation technique with water as solvent. The hardness studies of these crystals was done by Vicker’s hardness tester applying load in the range of 25 -100g.The hardness parameter increases with increase in load. The Meyer index of the crystals were found to be 3.67 for BTZA and 4.02 for L BTZA which indicates that both the crystals belong to soft material category. The elastic stiffness constant (C11) for different loads is calculated using Wooster's empirical formula which increases with increase in load. The yield strength,fracture toughness and brittle index of L BTZA is found to be more compared to BTZA. Keywords - Microhardness, Meyer Index, Yield Strength, Fracture Mechanics, Britteleness Index