Characterization of high-quality MgB2(0001) epitaxial films on Mg(0001)

TL;DR

This paper reports the successful growth and detailed characterization of high-quality MgB2(0001) epitaxial films on Mg(0001), including novel band mapping and electron-phonon coupling estimation, advancing understanding of their electronic properties.

Contribution

It presents the first band mapping along the Gamma-A direction and estimates the electron-phonon coupling constant for MgB2 surface electrons.

Findings

Epitaxially oriented MgB2 films with bulk structure formed on Mg substrates.

First band mapping along the Gamma-A direction for MgB2.

Estimated electron-phonon coupling constant of approximately 0.55.

Abstract

High-grade MgB2(0001) films were grown on Mg(0001) by means of ultra-high-vacuum molecular beam epitaxy. Low energy electron diffraction and x-ray diffraction data indicate that thick films are formed by epitaxially oriented grains with MgB2 bulk structure. The quality of the films allowed angle-resolved photoemission and polarization dependent x-ray absorption measurements. For the first time, we report the band mapping along the Gamma-A direction and the estimation of the electron-phonon coupling constant l ~ 0.55 for the surface state electrons.