New insight into the structural, mechanical, electronic, and thermodynamic properties of the monoclinicTMAl₃‐type aluminides

Abstract

Despite of the potential high-temperature technological applications of MoAl 3 alloy because of high-temperature strength and good oxidation resistance, the structure and related properties of the monoclinic TMAl 3 aluminides are entirely unclear. Here, we apply the first-principles calculation to study the structure, elastic, electronic, and thermodynamic properties of the monoclinic TMAl 3 . Five novel monoclinic TMAl 3 aluminides: ScAl 3 , TiAl 3 , VAl 3 , CrAl 3 , and WAl 3 are first predicted. The result shows that the hardness of the monoclinic TiAl 3 is 13.0 GPa, which is larger than the tetragonal TiAl 3 . In particular, the calculated elastic modulus and hardness of WAl 3 are larger than the other TMAl 3 because of the heavy valence electronic density of metal W. Importantly, it is first found that the monoclinic MoAl 3 shows the semiconductor properties with the band gap of 0.047 eV. In addition, the calculated Debye temperature of the monoclinic CrAl 3 is 537.6 K, which is larger than the other monoclinic TMAl 3 . Essentially, the thermal stability of the monoclinic TMAl 3 relies on the vibration of Al and Al Al bond.

Structural, Electronic, and Mechanical Properties of Ag‐Cu‐Ga Intermetallic Compounds: First‐Principles Calculations

“…The anisotropy characteristics of Ag 2 Ga and CuGa 2 crystals are further studied, and the elastic anisotropy of the crystals is represented in 3D graphs. The change of Young's modulus ( E ) with the direction of crystal can show the anisotropic behavior of crystalline phase, [ 37 ] and the directional dependence of Young's modulus is shown in Figure .…”

New insight into the structural and physical properties of AlH 3

“…Here, the atomic positions and lattice of AlH 3 are relaxed 42‐46 . The phonon calculations were performed by combining CASTEP code and PHONOPY package 47‐51 …”

“…[42][43][44][45][46] The phonon calculations were performed by combining CASTEP code and PHONOPY package. [47][48][49][50][51]…”

First‐principles investigation of the influence of point defect on the electronic and optical properties of α‐Ga 2 O 3

“…There is no doubt that the first-principles method is an effective tool to reveal the nature of various properties of a solid. [27][28][29][30][31][32] In this work, therefore, the vacancy stability, electronic and optical properties of the α-Ga 2 O 3 with O vacancy and Ga vacancy were calculated by the firstprinciples calculations, as implemented in CASTEP code. 33 The ultra-soft pseudopotential 34 was used to calculate the interaction of ionic core vs valence-electron.…”