Electronic and optical properties of the antifluorite semiconductors Be2C and Mg2X (, Si, Ge) under hydrostatic pressure

Synthesis of Mg2C: A Magnesium Methanide

“…These calculations provide EoS parameters (B 0 = 89.9 GPa, B' 0 = 4.02, and V 0 = 163. 3 3 ) that are in much better agreement with experiment than those previously reported for Mg 2 C, [8,17,22] and should serve as a basis for the calculation of more realistic electronic and optical properties. The ambient-pressure DFT (PBE) indirect (direct) bandgap of 0.67 eV (1.34 eV) calculated here is notably lower than those reported previously: 0.77 eV (1.8 eV) [17] and 0.97 eV (ca.…”

“…[17] Mg 2 C was assumed to take on the antifluorite structure and was predicted to be a highly ionic compound with a narrow indirect bandgap of about 1 eV. The 13 C NMR spectrum ( Figure 1 c) of Mg 2 13 C sample (99 % of isotopic purity) displays one resonance at d, + 102 ppm.…”

A First Principle Study of Antifluorite Be2X (X = C, Si) Polymorph

“…In part, this is due to the fact that this material tends to hydrolyze to Be(OH) 2 and to react with * corresponding author; e-mail: qunwei@xidian.edu.cn O and N. Experimentally, the electron-energy-loss studies on very small samples have been performed by Disko et al [6]. Theoretically, several calculations [7][8][9] have applied different density functional methods to explore the structural, electronic, and optical properties of Be 2 C. These studies suggest that Be 2 C is a semiconductor with large indirect gap which is leading to potential optical applications. To our knowledge, the mechanical behaviors of Be 2 X (X = C, Si) compounds are least studied, and there is a lack of reports on the thermal properties about these promising materials.…”

Numerical and Experimental Investigations on the Growth of the Intermetallic Mg2Si Phase in Mg Infiltrated Si‐Foams

“…There are two possible diffusionmechanisms, interstitial and substitution diffusion, [5,6] for the growth of the intermetallic layer. As reported in ref., [7] the magnesium silicide has an antifluorite structure, which is illustrated in Figure 1b. The atomic radius for Mg and Si is 160.2 and 117.6 pm, respectively.…”