First-principles calculations to investigate structural and elastic properties of Y2C3 under external pressure

Abstract

Abstract The structural and elastic properties of Y2C3 have been studied under ambient to 160 GPa pressure using first principles method based on density functional theory. New bond formation of C-C and Y-Y were observed at 50 GPa and 140 GPa, respectively. Bond lengths of C-C, C-Y, and Y-Y are decreased with increase of pressure and maximum value was found to be 0.39093 A for C-Y-2 bond. Anisotropy of bond lengths was observed due to displacement of Y and C atoms along the different directions. Y2C3 was found to be mechanically stable up to 160 GPa. Elastic constants and moduli showed anomaly at 50 GPa which may be due to pressure induced structural phase change. Poor/non-metallic behavior of Y2C3 was changed to metallic under external pressure. Anisotropic nature was observed below and above 80 GPa. The Vickers hardness H V B = 40.80 GPa at 70 GPa implies that Y2C3 becomes super-hard materials.