Hydrostatic Pressure Dependence of the Superconducting and Structural Properties of MgB2

TL;DR

This study investigates how hydrostatic pressure affects the superconducting transition temperature and structure of MgB2 using in situ neutron diffraction and high-pressure measurements, supporting electron-phonon pairing mechanisms.

Contribution

It provides comprehensive pressure-dependent data on MgB2's structural and superconducting properties using multiple experimental techniques.

Findings

Tc decreases with pressure up to 0.6 GPa

Structural changes correlate with Tc variation

Results support electron-phonon pairing in MgB2

Abstract

In this paper we report parallel in situ neutron powder diffraction and Tc(P) measurements versus pressure on the same MgB2 sample in a He-gas apparatus to 0.6 GPa; in addition, we present Tc(P) measurements in a helium-loaded diamond-anvil-cell to 20 GPa on the same sample. Our results are compared with those of other groups. The high precision achieved in these measurements allows a quantitative evaluation of the change in Tc as a function of the changes in structure. Our results are consistent with electron-phonon pairing in MgB2.