TY - JOUR AU - Neupane, Hari Krishna AU - Adhikari, Narayan Prasad PY - 2020/12/31 Y2 - 2024/03/29 TI - First-principles study of C cites vacancy defects in water adsorbed Graphene JF - Himalayan Physics JA - Himalayan Physics VL - 9 IS - 01 SE - Research Articles DO - 10.3126/hp.v9i01.40150 UR - https://www.nepjol.info/index.php/HP/article/view/40150 SP - 19-29 AB - <p>&nbsp;The electronic and magnetic properties of water adsorbed graphene (w<sub>ad </sub>– G), single carbon (1C) atom vacancy defects in water adsorbed graphene (1C<sub>atom-vacancy </sub>– w<sub>ad </sub>– G) and double carbon (2C) atoms vacancy defects in water adsorbed graphene (2C<sub>atom-vacancy </sub>– w<sub>ad </sub>– G) materials are studied by first-principles calculations within the frame work of density functional theory (DFT) using computational tool Quantum ESPRESSO (QE) code. We have calculated the binding energy of w<sub>ad </sub>– G, 1C<sub>atom-vacancy </sub>– w<sub>ad </sub>– G and 2C<sub>atom-vacancy </sub>– w<sub>ad </sub>– G materials, and then found that non-defects geometry is more compact than vacancy defects geometries. From band structure calculations, we found that w<sub>ad </sub>– G is zero band gap semiconductor, but 1C<sub>atom-vacancy </sub>– w<sub>ad </sub>– G and, 2C<sub>atom-vacancy </sub>– w<sub>ad </sub>– G materials have metallic properties. Hence, zero band gap semiconductor changes to metallic nature due to C sites vacancy defects in its structures. We have investigated the magnetic properties of w<sub>ad </sub>– G and its C sites vacancy defects materials by using Density of States (DOS) and Partial Density of States (PDOS) calculations. We found that w<sub>ad </sub>– G is non- magnetic material. 1C atom vacancy defects in graphene surface of w<sub>ad </sub>– G is induced magnetization by the re-bonding of two dangling bonds and acquiring significant magnetic moment (0.11 µB/ cell) through remaining unsaturated dangling bond. But, 2C atoms vacancy defects in graphene surface of w<sub>ad </sub>– G induced low value of magnetic moment (+0.03 µB/ cell) than 1C atom vacancy defects in structure, which is due to no dangling bonds present in the structure. Therefore, non-magnetic, w<sub>ad </sub>– G changes to magnetic, 1C<sub>atom-vacancy </sub>– w<sub>ad </sub>– G and, 2C<sub>atom-vacancy </sub>– w<sub>ad </sub>– G materials due to C sites vacancy defects in w<sub>ad </sub>– G structure. The 2p orbital of carbon atoms has main contribution of magnetic moment in defects structures.</p> ER -