Research Paper: Investigation of Electronic and Structure Properties of MgB2 Superconductor by Ab-initio Method

Document Type : Research Paper

Authors

1 Associate Professor, Department of Physics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran

2 M. Sc. Graduated, Department of Physics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran.

Abstract

The structural of MgB2 such as lattice constant, volume modulus, volume modulus derivative and compressibility of different degrees have been calculated. The calculations have been performed using a Full Potential-Linearized Augmented Plane Wave (FP-LAPW) method in the framework of Density Functional Theory (DFT) with various Approximation. The results show that the linear compressibility in direction of c is about twice the compressibility in direction of a. In addition, the electronic properties of the compound, including the structure of the energy bands, the density of the states, and the types of bonds in the MgB2 Superconductivity have been studied. The results of a double degeneracy above the Fermi level show that it plays an important role in the superconducting property. According to energy bands, it has been determined that the lattice parameters have a large effect on the s band of boron atoms. The results predict that the constant increase of the lattice along the c-axis has an increase in the density of states at the Fermi level. The results express this fact that the calculation using by GGA has the better agreements with the other theoretical and experimental approximations.

Keywords


[1] Buzea D. and Yamashita T, “Review of superconducting properties of MgB2Supercond. Sci. Technol 14, R115(2001).
[2] Jones M E and Marsh R E, “The Preparation and Structure of Magnesium Boride, MgB2J. Am. Chem. Soc. 76, 1434-1436(1954).
[3] Kortus J, Mazin I I et al., “Superconductivity of Metallic Boron in MgB2”, Phys. Rev. Lett 8, 4656-4659(2001).
[4] Kong Y, Dolgov O V et al., “Electron-phonon interaction in the normal and superconducting states of MgB2Phys. Rev. B 64, 020501(R), (2001).
[5] Demeter T  and Aristides M, “Ab Initio Investigation of the Electronic and Geometric Structure of Magnesium Diboride, MgB2”, J. Phys. Chem. A109, 47؛10663–10674( 2005).
[6] Alexander S S and Boris I L, “Structure and properties of (AlB2)n and (MgB2)n (n = 1, …, 10) clusters”, The European Physical Journal D 73, 14(2019) .
[7] Islam A K M A, Islam F N and Kabir S, “Ab initio investigation of mechanical behaviour of MgB2 superconductor under pressure”, Journal of Physics: Condensed Matter 13, L641 (2001).
[8] Vinod K, Varghese N and Syamaprasad U, “Superconductivity of MgB2 in the BCS framework with emphasis on extrinsic effects on critical temperature”, Superconductor Science and Technology 20, R31, (2007).
[9] Boeri L, “Understanding Novel Superconductors with Ab Initio Calculations”, arXiv:1903.05708,2019.
[10] Blaha P, and Schwarz K, Wien2k, Viena university of Technology Austria (2009).
[11] Perdew J P, Burke K, Ernzerhof M, “Generalized Gradient Approximation Made Simple”, Phys. Rev. Lett 77,3865-3868(1996).
[12] Loa I, Kunc K, and Syassen K, “Crystal structure and lattice dynamics of AlB2 under pressure and implications for MgB2”, Phys. Rev. B 66, 134101(2002).
[13] Prassides K, Iwasa Y, Ito T et al., “Compressibility of the MgB2 superconductor”, Phys. Rev. B 64, 012509(2001).
[15] Voget T, Schneider G et al., “Compressibility and electronic structure of MgB2 up to 8GPa”, Phys. Rev. B 63, 220505(2001).
[16] Jie T, Lu-chang Qin et al., “Lattice parameter and Tc dependence of sinteral MgB2 superconductor on hydrostatic pressure”, Phys. Rev. B 64, 132509-4(2001).