Energetics of Mg and B adsorption on polar zinc oxide surfaces from first principles

Abstract

We have performed first-principles density-functional projector augmented-wave calculations to investigate the energetics of Mg and B adsorption on polar zinc oxide ͑ZnO͒ surfaces, thereby to understand the origin of the peculiar affinities between an epitaxial MgB 2 film and the ZnO substrate. We found that the ͑0001͒ Zn surface is relatively inert, while the ͑0001͒ O surface is very reactive in the adsorption of atomic species, where a triplaner BO 3 ͑a hump of MgO 3 ͒ binding unit is formed as a consequence of the B ͑Mg͒ atom adsorption on the surface. These binding units would be formed at an early stage in the epitaxial growth of MgB 2 film on the ZnO substrate, and subsequently lead to the formation of the reaction products that were recently found in the interface between the MgB 2 film and the ZnO substrate.

DFT simulation of the occurrences and correlation of gold and arsenic in pyrite

“…Here, the formation energy of a site-defect element in the pyrite lattice, ΔE, is defined as follows (Nishidate et al 2008):…”

Enhancement of critical current density for nano (n)-ZnO doped MgB2 superconductor

“…Amongst nano-dopants, the nano (n)-ZnO has been taken into account because the local structure of MgB 2 should be affected by Mg-O interaction on the ZnO. In the recent years, various studies have been reported experimentally [28][29][30][31][32][33][34] and theoretically [35][36][37][38][39] for the enhancement of superconducting properties in Zn-doped MgB 2 superconductor. Various attempts have been made for enhancing J c , H c2 and H irr by doping different organic and inorganic Zn-containing materials in MgB 2 as reported earlier [40,41].…”

Polarized XAFS study of Mg K-edge for MgB2 on ZnO

“…Superconductor MgB 2 was discovered in 2001 and shows the superconducting transition temperature of 39 K which is the highest for metal compounds. The superconducting mechanism and applications as a device are attracting great interest.…”

“…For this purpose, various methods of film growth have been investigated. A c c e p t e d M a n u s c r i p t calculations of the interaction between MgB 2 and ZnO have been done [2]. For studying the local structure of such thin films, EXAFS (Extended X-ray Absorption Fine Structure) is a powerful tool.…”