Superconductivity of the Ternary Boride Li_2Pd_3B Probed by ^{11}B NMR

TL;DR

This study uses ^{11}B NMR to investigate the superconducting properties of Li_2Pd_3B, revealing conventional superconductivity with an isotropic gap and identifying key electronic contributors.

Contribution

First ^{11}B NMR analysis of Li_2Pd_3B demonstrating conventional superconductivity and electron contributions from boron p and palladium d orbitals.

Findings

Observation of a coherence peak in 1/T_1 below T_c

Decrease in Knight shift indicating spin susceptibility reduction

Superconductivity characterized as conventional with an isotropic gap

Abstract

We report a ^{11}B NMR measurement on the recently discovered superconductor Li_2Pd_3B. The nuclear spin lattice relaxation rate 1/T_1 shows a well-defined coherence peak just below T_c (H=1.46 T)=5.7 K, and the spin susceptibility measured by the Knight shift also decreases below T_c. These results indicate that the superconductivity is of conventional nature, with an isotropic gap. Our results also suggest that the $p$-electrons of boron and the d-electrons of palladium that hybridize with boron $p$-electrons are primarily responsible for the superconductivity.