First Principles Study of Structural, Electronic, Mechanical and Density of State Properties of the Half - heusler Alloy NaCrGe
Emmanuel Benjamin Ettah
*
Cross River University of Technology Calabar Nigeria.
*Author to whom correspondence should be addressed.
Abstract
In this study, the investigated structural parameters revealed that NaCrGe is stable at beta phase. We obtained that the material is a narrow bandgap semiconductor half-Heusler alloys with measured gap of 1.050 eV. The structure NaCrGe conduction band minimum (CBM) position at gamma(Γ) and the valence band maximum (VBM) located at X-point of the Brillouin zone. This indicates that the alloy NaCrGe has indirect bandgap semiconductors. The material NaCrGe is considered hybrids between metals and semiconductors. Hence, NaCrGe is Half-metallic heusler alloy. The calculated mechanical properties indicate that NaCrGe possesses good mechanical stability, making it suitable for structural applications. B/G ratio for NaCrGe is 2.40. This implies that NaCrGe is “ductile” in nature at ambient condition. Also NaCrGe is confirmed “ductile” in nature at positive value of C11 – C44 (+48.07). PDOS shows that Na-4p, Cr-4p and Ge- 2p has the highest orbital contribution for Na, Cr and Ge atoms respectively. At fermi energy both spin up and spin down is at zero point in the plot of projected density of state (PDOS) against energy. This revealed that NaCrGe is a half metallic heusler alloy.
Keywords: Half heusler, half-metallic gap, electronic band structure, mechanical properties, density of state, alloys