Influence of Rb, Cs and Ba on Superconductivity of Magnesium Diboride

TL;DR

This study investigates how Rb, Cs, and Ba influence the superconducting properties of magnesium diboride, revealing changes in critical temperature and local electronic symmetry due to different elemental treatments.

Contribution

It demonstrates the effects of Rb, Cs, and Ba on MgB2's superconductivity and local electronic environment, providing new insights into doping and treatment impacts.

Findings

Superconducting transition temperatures: 52K (Rb), 58K (Cs), 45K (Ba).

Different treatments alter the symmetry of the electric field gradient at boron sites.

Magnetic susceptibility confirms onset of superconductivity in all samples.

Abstract

Magnesium diboride has been thermally treated in the presence of Rb, Cs, and Ba. Magnetic susceptibility shows onsets of superconductivity in the resulting samples at 52K (Rb), 58K (Cs) and 45K (Ba). Room-temperature 11B NMR indicates to cubic symmetry of the electric field gradient at boron site for the samples reacted with Rb and Cs, in contrast to the axial symmetry in the initial MgB2 and in the sample treated with Ba.