Suppression of Superconductivity in Lu$_x$Zr$_{1-x}$B$_{12}$ : Evidence of Static Magnetic Moments Induced by Non-Magnetic Impurities

TL;DR

This study reveals that non-magnetic lutetium impurities in Lu$_x$Zr$_{1-x}$B$_{12}$ superconductors induce static magnetic moments, significantly suppressing superconductivity through local spin polarization effects.

Contribution

It provides evidence that non-magnetic impurities can create static magnetic moments, leading to superconductivity suppression in Lu$_x$Zr$_{1-x}$B$_{12}$, a novel insight into impurity effects.

Findings

Superconductivity is strongly suppressed for x<0.08.

Non-magnetic Lu impurities induce static magnetic moments.

Magnetic moments are approximately 3 μ_B per Lu-ion.

Abstract

Based on low temperature resistivity, heat capacity and magnetization investigations we show that the unusually strong suppression of superconductivity in Lu$_x$Zr$_{1-x}$B$_{12}$ BSC-type superconductors in the range $x$$<$0.08 is caused by the emergence of static spin polarization in the vicinity of non-magnetic lutetium impurities. The analysis of received results points to a formation of static magnetic moments with $\mu_{eff}$$\approx$$3\mu_B$ per Lu-ion. The size of these spin polarized nanodomains was estimated to be about 5 ${\AA}$.