Epitaxial MgB2 thin films on ZrB2 buffer layers: structural characterization by synchrotron radiation

TL;DR

This study investigates the structural and superconducting properties of MgB2 thin films grown on ZrB2 buffer layers, demonstrating high-quality epitaxial growth and superconducting performance comparable to the best reported values.

Contribution

It provides new insights into the epitaxial growth process of MgB2 on ZrB2 buffers and demonstrates the effectiveness of synchrotron radiation in structural characterization.

Findings

Single in-plane orientation of layers confirmed by synchrotron diffraction

Buffer layer prevents oxygen contamination from substrate

Critical temperature of 37.6 K and high upper critical field achieved

Abstract

Structural and superconducting properties of magnesium diboride thin films grown by pulsed laser deposition on zirconium diboride buffer layers were studied. We demonstrate that the ZrB2 layer is compatible with the MgB2 two step deposition process. Synchrotron radiation measurements, in particular anomalous diffraction measurements, allowed to separate MgB2 peaks from ZrB2 ones and revealed that both layers have a single in plane orientation with a sharp interface between them. Moreover, the buffer layer avoids oxygen contamination from the sapphire substrate. The critical temperature of this film is near 37.6 K and the upper critical field measured at Grenoble High Magnetic Field Laboratory up to 20.3 T is comparable with the highest ones reported in literature.