Studies of microhardness anisotropy and Young's modulus of nonlinear optical crystal l-arginine hydrochlorobromo monohydrate

In this communication hardness anisotropy of first order and second order has been studied for a new nonlinear optical crystal l-arginine hydrochlorobromo monohydrate (LAHClBr). We have employed Vickers and Knoop indentation method for the measurement of microhardness and Young's modulus of LAHClBr. The results are also verified by ultrasonic velocity measurement. Both the values of microhardness and Young's modulus reveal that (100) plane is the softest one and (100)<010> is identified as one of the slip system. Overall studies also show that LAHClBr belongs to the soft crystal category.