Ab initio calculations on nuclear quadrupole interactions of 69,71Ga and 14N nuclei in GaN of ionic crystal

• Published in: Physica. B, Condensed matter Condensed matter, 2008-07, Vol.403 (13), p.2225-2229
• Main Authors: Jeong, Junho, Choh, S.H., Sahoo, N., Das, T.P.
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Crystal binding; cohesive energy; Crystalline state (including molecular motions in solids); Exact sciences and technology; GaN; Hartree-Fock Roothaan method; Ionic crystal; Madelung potential; Nuclear quadrupole interactions; Physics; Structure of solids and liquids; crystallography
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2007.11.036

This paper presents the results of our calculation of nuclear quadrupole coupling constant (NQCC) of 69,71Ga and 14N on wurtzite GaN crystal using the Hartree-Fock Roothaan Molecular Cluster procedure. We employed Ga 4N 4H 18 cluster as well as the (GaN 4) 9− and the (NGa 4) 9+ clusters surrounded by 1160 external Ga 3+ and N 3− ions in 15 Å radius lattice to simulate the covalent bonding and ionic bonding among the constituent atoms in the solid-state system and to calculate the electronic structure and the associated nuclear quadrupole interaction properties of 14N and 69,71Ga. The nuclear quadrupole coupling constant (NQCC) e 2 qQ/h for 69Ga with a value of its Q as 0.168 barns was found to be 2.98 MHz in the (GaN 4) 9− cluster and 34.43 MHz in the Ga 4N 4H 18 cluster. The e 2 qQ/h for the 14N in the (NGa 4) 9+ cluster representing the ionic bonding was found to be 0.0303 MHz using the nuclear quadrupole moment of 14N nucleus as 0.0193 barns. The calculated NQI parameters from the (GaN 4) 9− and the (NGa 4) 9+ clusters agree well with the experimental values indicating the existence of the significant ionic bonding between the constituent atoms in the solid-state system.