Lattice dynamical and thermo-elastic properties of M2AlB (M = V, Nb, Ta) MAX phase borides

2020-04-05
Surucu, Gokhan
Gencer, Ayşenur
Wang, Xiaotian
Surucu, Ozge
The structural, electronic, dynamic, and thermo-elastic properties of M2AlB (X = V, Nb, Ta) MAX phase borides were investigated using first principle calculations as implemented in the Vienna Ab-initio Simulation Package (VASP) with the generalized gradient approximation (GGA). The obtained structural properties and formation energies showed the thermodynamic stability and synthesizability of M2AlB. The electronic band structures were determined and they revealed that these compounds had a metallic character. The dynamic stability of M2AlB compounds were investigated with phonon dispersion curves and these compounds were found to be dynamically stable. The elastic constants were also calculated to determine the mechanical stability and to obtain the polycrystalline properties such as bulk modulus, shear modulus, etc. The thermo-elastic properties (thermal expansion coefficient, heat capacity, entropy, and free energy) were studied in a temperature range in between 0 and 1000 K and a pressure range in between 0 and 30 GPa. In addition, the direction dependent sound wave velocities were studied in three dimensions. Moreover, the minimum thermal conductivities and the diffusion thermal conductivities of these compounds were determined. This work is the processor study for the investigation of the main physical properties of M2AlB (M = V, Nb, Ta) ceramic compounds to date.
JOURNAL OF ALLOYS AND COMPOUNDS

Suggestions

Numerical and experimental determination of the residual stress state in multipass welded API 5LX70 plates
Garipova, Nuriya; Batıgün, Caner; Gür, Cemil Hakan (2014-01-01)
Residual stres s distributions in multipass welded API SL X70 steel plates were determined by numerical and experimental methods. SYSWELD finite element software was used for numerical simulations. Microstructure variations were also considered for calculation of residual stresses. The continuous cooling transformation diagram was obtained via JMatPro software. The results showed that residual stress distribution is sensitive to number of weld passes, and microstructure changes. The simulation results were ...
Computational modeling of isothermal decay curves of trapping centers in TlGaSeS layered single crystals
Kucuk, Ilker; Yildirim, Tacettin; Hasanlı, Nızamı; Ozkan, Husnu (Elsevier BV, 2010-10-08)
This paper presents a new approach based on multilayered perceptrons (MLPs) to compute the isothermal decay curves of trapping centers in undoped TlGaSeS layered crystals. The MLP has been trained by a Genetic Algorithm (GA). The results obtained using the MLP model were tested with an untrained experimental data. The comparison has shown that the proposed model can predict more accurately and easily the isothermal decay curves.
Size dependent stability and surface energy of amorphous FePt nanoalloy
Akdeniz, Mahmut Vedat; Mehrabov, Amdulla (Elsevier BV, 2019-06-05)
The effects of particle size (2-6 nm) and temperature (300-2700 K) on the stability and local structural evolutions of amorphous equiatomic FePt bulk/nanoalloys have been investigated by combining Embedded Atom Model (EAM) with classical molecular dynamics (MD) simulation method. The three dimensional (3D) atomic configuration of amorphous FePt NPs by means of Voronoi analysis reveals that, deformed bcc (d-bcc) and icosahedron (d-ico) type structures are most probable local atomic configurations for 2-6 nm ...
Temperature dependence of the isothermal bulk modulus of TiB2
Ozkan, H. (Elsevier BV, 2011-04-01)
The temperature dependencies of the isothermal bulk modulus of TiB2 above room temperature were calculated by using the equation for the Anderson- Gruneisen parameter (delta(T)) and its solution by Garai and Laugier (J. Appl. Phys. 101, 023514 (2007)). The present calculations utilize the relevant experimental data for the pressure derivative of the isothermal bulk modulus, K' as delta(T) in addition to the volume thermal expansion coefficients (alpha(V)). The temperature derivatives of the isothermal bulk ...
Acoustic phonons scattering mobility and carrier effective mass in In6S7 crystals
Qasrawi, A. F.; Hasanlı, Nızamı (Elsevier BV, 2006-12-21)
Systematic dark electrical resistivity and Hall coefficient measurements have been carried out in the temperature range of 170-320 K on n-type In6S7 crystals. The analysis of the electrical resistivity and carrier concentration reveals the intrinsic type of conduction with an average energy band gap of similar to 0.75 eV The carrier effective masses of the conduction and valence bands were calculated from the intrinsic temperature-dependent carrier concentration data and were found to be 0.565m(0) and 2.020...
Citation Formats
G. Surucu, A. Gencer, X. Wang, and O. Surucu, “Lattice dynamical and thermo-elastic properties of M2AlB (M = V, Nb, Ta) MAX phase borides,” JOURNAL OF ALLOYS AND COMPOUNDS, pp. 0–0, 2020, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/51897.