Microhardness studies on nonlinear optical 𝐿-alanine single crystals

[摘要] Vickers and Knoop microhardness tests were carried out on grown 𝐿-alanine single crystals by slow evaporation technique over a load range of 10â€�??50 g on selected broad (2 0 3) plane. Vickers (𝐻_v) and Knoop (𝐻_k) microhardness for the above loads were found to be in the range of 60â€�??71 kg/mm² and 35â€�??47 kg/mm², respectively. Vickers microhardness number (𝐻_v) and Knoop microhardness number (𝐻_k) were found to increase with increasing load. Meyer’s index number (ð‘�??) calculated from 𝐻_v shows that the material belongs to the soft material category. Using Wooster’s empirical relation, the elastic stiffness constant (ð‘�?₁₁) was calculated from Vickers hardness values. Young’s modulus was calculated using Knoop hardness values. Hardness anisotropy has been observed in accordance with the orientation of the crystal.

[学科分类] 材料工程

[关键词] Organic compounds;mechanical properties;hardness;anisotropy.