Lattice dynamic properties of BaSi2 and BaGe2 from first principle calculations

2010 ◽  
Vol 374 (36) ◽  
pp. 3797-3800 ◽  
Author(s):  
H. Peng ◽  
C.L. Wang ◽  
J.C. Li ◽  
R.Z. Zhang ◽  
M.X. Wang ◽  
...  
Keyword(s):  
Dynamic Properties ◽  
Lattice Dynamic ◽  
First Principle ◽  
First Principle Calculations

scholarly journals Phase Stability and Mechanical Properties of Al8Fe4RE via First-Principle Calculations

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 701
Author(s):  
Rongcheng Wang ◽  
Xiaoma Tao ◽  
Hongmei Chen ◽  
Yifang Ouyang
Keyword(s):  
Young’S Modulus ◽  
Phase Stability ◽  
Young's Modulus ◽  
Dynamic Properties ◽  
First Principle ◽  
Lattice Constants ◽  
First Principle Calculations ◽  
Phonon Spectra ◽  
Calculated Enthalpy ◽  
3D Surfaces

We report on the phase stability, elastic, electronic, and lattice dynamic properties of 17 Al8Fe4RE (RE = Sc, Y, La–Lu) intermetallic compounds (IMCs) using first-principle calculations. The calculated lattice constants coincided with the experimental results. The calculated enthalpy formation indicated that all the 17 IMCs are stable. The elastic constants and various moduli indicated that Al8Fe4RE can be used as a strengthening phase due to its high Young’s modulus and shear modulus. The 3D surfaces of Young’s modulus for Al8Fe4RE showed anisotropic behavior, and the values of hardness for the IMCs were high (about 14 GPa). The phonon spectra showed that only Al8Fe4Y had a soft mode, which means the other IMCs are all dynamically stable.

Structural, electronic, optical and lattice dynamic properties of the different WO3 phases: First-principle calculation

Vacuum ◽  
2019 ◽  
Vol 164 ◽  
pp. 411-420 ◽  
Author(s):  
Huanhuan Yang ◽  
Honggang Sun ◽  
Qiutong Li ◽  
Pan Li ◽  
Kaikai Song ◽  
...  
Keyword(s):  
Dynamic Properties ◽  
Lattice Dynamic ◽  
First Principle ◽  
Principle Calculation ◽  
First Principle Calculation ◽  
Wo3 Phases

Optical phonons in the kesterite Cu2ZnGeS4 semiconductor: polarized Raman spectroscopy and first-principle calculations

RSC Advances ◽  
2016 ◽  
Vol 6 (16) ◽  
pp. 13278-13285 ◽  
Author(s):  
M. Guc ◽  
A. P. Litvinchuk ◽  
S. Levcenko ◽  
M. Ya. Valakh ◽  
I. V. Bodnar ◽  
...  
Keyword(s):  
Vibrational Analysis ◽  
Lattice Dynamic ◽  
First Principle ◽  
Optical Phonons ◽  
Plane Rotation ◽  
Crystal Facet ◽  
First Principle Calculations ◽  
Scattering Measurements ◽  
Polarized Raman Spectroscopy ◽  
Polarized Raman

A comprehensive vibrational analysis of the kesterite Cu2ZnGeS4 is reported, which includes in-plane rotation polarized Raman scattering measurements from the (1 0 1)-single crystal facet as well as first principle lattice dynamic calculations.

scholarly journals A First-Principle Study of Monolayer Transition Metal Carbon Trichalcogenides

2021 ◽  
Author(s):  
Muhammad Yar Khan ◽  
Yan Liu ◽  
Tao Wang ◽  
Hu Long ◽  
Miaogen Chen ◽  
...  
Keyword(s):  
Phonon Dispersion ◽  
Magnetic Ordering ◽  
Dimensional Structure ◽  
First Principle ◽  
Two Dimensional ◽  
Biaxial Strain ◽  
Half Metallic ◽  
First Principle Calculations ◽  
Potential Applications ◽  
External Strain

AbstractMonolayer MnCX3 metal–carbon trichalcogenides have been investigated by using the first-principle calculations. The compounds show half-metallic ferromagnetic characters. Our results reveal that their electronic and magnetic properties can be altered by applying uniaxial or biaxial strain. By tuning the strength of the external strain, the electronic bandgap and magnetic ordering of the compounds change and result in a phase transition from the half-metallic to the semiconducting phase. Furthermore, the vibrational and thermodynamic stability of the two-dimensional structure has been verified by calculating the phonon dispersion and molecular dynamics. Our study paves guidance for the potential applications of these two mono-layers in the future for spintronics and straintronics devices.

scholarly journals Quantitative Evaluations of Hydrogen Diffusivity in V-X (X = Cr, Al, Pd) Alloy Membranes Based on Hydrogen Chemical Potential

Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 67
Author(s):  
Asuka Suzuki ◽  
Hiroshi Yukawa
Keyword(s):  
Nearest Neighbor ◽  
Chemical Potential ◽  
Hydrogen Permeability ◽  
First Principle ◽  
Hydrogen Diffusivity ◽  
Hydrogen Atoms ◽  
First Principle Calculations ◽  
Blocking Effects ◽  
Pd Alloy ◽  
Quantitative Evaluations

Vanadium (V) has higher hydrogen permeability than Pd-based alloy membranes but exhibits poor resistance to hydrogen-induced embrittlement. The alloy elements are added to reduce hydrogen solubility and prevent hydrogen-induced embrittlement. To enhance hydrogen permeability, the alloy elements which improve hydrogen diffusivity in V are more suitable. In the present study, hydrogen diffusivity in V-Cr, V-Al, and V-Pd alloy membranes was investigated in view of the hydrogen chemical potential and compared with the previously reported results of V-Fe alloy membranes. The additions of Cr and Fe to V improved the mobility of hydrogen atoms. In contrast, those of Al and Pd decreased hydrogen diffusivity. The first principle calculations revealed that the hydrogen atoms cannot occupy the first-nearest neighbor T sites (T1 sites) of Al and Pd in the V crystal lattice. These blocking effects will be a dominant contributor to decreasing hydrogen diffusivity by the additions of Al and Pd. For V-based alloy membranes, Fe and Cr are more suitable alloy elements compared with Al and Pd in view of hydrogen diffusivity.

scholarly journals Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Durga Sankar Vavilapalli ◽  
Ambrose A. Melvin ◽  
F. Bellarmine ◽  
Ramanjaneyulu Mannam ◽  
Srihari Velaga ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
First Principle ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Principle Calculations ◽  
Photodegradation Efficiency

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

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