D.S. Jayalakshmi; M. Nasreen Banu; M. Sundareswari; D. Hemanand; E. Viswanathan
Abstract
The structural, bonding, magnetic, electronic, elastic and thermoelectric nature of superconducting material namely MgB2, with hexagonal structure (space group is 191) are studied by first principle calculation. The optimized lattice parameters of MgB2 are a=b=3.084289 Ǻ and c= 3.51527 Ǻ ...
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The structural, bonding, magnetic, electronic, elastic and thermoelectric nature of superconducting material namely MgB2, with hexagonal structure (space group is 191) are studied by first principle calculation. The optimized lattice parameters of MgB2 are a=b=3.084289 Ǻ and c= 3.51527 Ǻ and the electron phonon coupling constant (λ), Debye temperature, critical temperature, Seebeck coefficient, electrical resistivity and the elastic constants (C11, C12, C13, C33, C55) are calculated and agreed well with available outcome. To predict other possible superconducting materials belong to MgB2 family, Mg is further doped with transition element Titanium (Ti) and analyzed. Copyright © VBRI Press.
Meena Kumari; Manju Sikarwar; U.P. Verma
Abstract
In this paper DyMg alloy has been studied in three phases viz. B1, B2 and B3. The exchange correlation potential within the generalized-gradient approximation (GGA) of projector augmented wave (PAW) method is used. The predicted lattice constants and total energy at ambient condition, respectively ...
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In this paper DyMg alloy has been studied in three phases viz. B1, B2 and B3. The exchange correlation potential within the generalized-gradient approximation (GGA) of projector augmented wave (PAW) method is used. The predicted lattice constants and total energy at ambient condition, respectively in B1, B2 and B3 phases are 6.395, 3.772, 6.40 Å, and -24734.778, -24734.855, -24734.683 Ry. From the calculations it is evident that ground state phase of DyMg is B2, therefore, other parameters such as the bulk modulus, its pressure derivative, elastic constants and thermal properties related to B2 phase are presented in this paper. The obtained results are compared with the available experimented and theoretical data. The calculated band structure shows that this alloy no band gap. In order to obtain more information about the elastic properties other parameters such as Zener anisotropy factor, Poisson ratio, Young’s modulus and isotropic shear modulus are also presented. Thermal parameter such as Debye temperature, specific heat, Gruneisen parameter etc. has been determined as a function of pressure and temperature. Copyright © 2017 VBRI Press.
