2 results
Search Results
Now showing 1 - 2 of 2
Article Citation - WoS: 8Citation - Scopus: 9First-principles studies of Tin+1SiNn (n=1, 2, 3) MAX phase(Taylor & Francis Ltd, 2020) Surucu, Gokhan; Gullu, Hasan Huseyin; Candan, Abdullah; Yildiz, Bugra; Erkisi, AytacIn this study, the structural, electronic, mechanical, lattice dynamical and thermodynamic characteristics of ( 1, 2 and 3) phase compounds were investigated using the first principle calculations. These ternary nitride compounds were found to be stable and synthesisable, and the results on the stability nature of them were also evaluated for the possible and phases. -was found to be the most stable one among these new class of layered phases for which limited works are available in the literature. The band structures, that are essential for the electronic properties, were determined along with the partial density of states (PDOS) indicating the metallic behaviour of these compounds. The polycrystalline elastic moduli were calculated based on the single-crystal elastic constants and the mechanical stabilities were verified. Some basic physical parameters, such as bulk modulus, shear modulus, Young's modulus, Poisson's ratio, Debye temperature, and sound velocities, were also predicted. Furthermore, the anisotropic elastic properties were visualised in three dimensions (3D) for Young's modulus, linear compressibility, shear modulus and Poisson's ratio as well as with the calculation of the anisotropic factors. - phase showed the most isotropic characteristics with minimum deviations. These theoretical values were also used to identify the stiffness and ionic characteristics. The phonon dispersion curves and corresponding PDOS indicated that compounds were dynamically stable. Moreover, thermodynamic properties obtained from phonon dispersion curves were investigated in detail.Article Citation - WoS: 23Citation - Scopus: 24First Principles Study on the Structural, Electronic, Mechanical and Lattice Dynamical Properties of Xrhsb (x = Ti and Zr) Paramagnet Half-Heusler Antimonides(Iop Publishing Ltd, 2019) Surucu, Gokhan; Candan, Abdullah; Erkisi, Aytac; Gencer, Aysenur; Gullu, Hasan HuseyinThe half-Heusler TiRhSb and ZrRhSb alloys in the formation of face-centered cubic MgAgAs-type structure, which conforms to the F (4) over bar 3m space group with 216 as the space number, have been investigated using Generalized Gradient Approximation (GGA) implemented in Density Functional Theory (DFT). The calculated formation enthalpies and the plotted energy-volume curves of different types of structural phases (alpha, beta, and gamma) in these alloys indicate that the gamma-phase structure is the best energetically suitable structure. In addition, TiRhSb and ZrRhSb alloys have been found as paramagnetic (PM) with the investigation of antiferromagnetic (AFM), ferromagnetic (FM), and paramagnetic (PM) orders in the most stable gamma-phase structure. Therefore, their electronic, mechanical, and dynamical properties have been examined in the gamma structural phase and paramagnetic order. These alloys have semiconducting nature due to the observed same band gaps in both the majority and minority spin channels of the calculated spin-polarised electronic band structure. These calculated band gaps are 0.75 eV for gamma-TiRhSb and 1.18 eV for gamma-ZrRhSb. The predicted elastic constants indicate that the alloys in this study are mechanically stable and show nearly isotropic behavior in the gamma structural phase. Also, the minimum and the diffuson thermal conductivites have been determined for these alloys. Finally, the calculated phonon dispersion spectras for the gamma-TiRhSb and gamma-ZrRhSb half-Heusler antimonide alloys show the dynamic stability of these systems.
