Nonvolatile magneto-thermal switching driven by vortex trapping in commercial In-Sn solder

TL;DR

This paper demonstrates that commercial In-Sn solder exhibits nonvolatile magneto-thermal switching due to vortex trapping in phase-separated superconducting regions, expanding understanding of nonvolatile MTS mechanisms.

Contribution

It reveals that In-Sn solder acts as a phase-separated superconductor with vortex trapping, providing new insights into nonvolatile MTS in superconducting composites.

Findings

In-Sn solder is a phase-separated superconductor with two Tc.

Vortices are trapped mainly in the lower-Tc phase after field cooling.

Nonvolatile MTS observed at 2.5 K due to vortex trapping.

Abstract

Magneto-thermal switching (MTS) is a key technology for efficient thermal management. Recently, large MTS with nonvolatility has been observed in Sn-Pb solders [H. Arima et al., Commun. Mater. 5, 34 (2024)] where phase separation, different superconducting transition temperature (Tc) of Sn and Pb, and magnetic-flux trapping are the causes of the nonvolatile MTS. To further understand the mechanism and to obtain the strategy for enhancing switching ratio, exploration of new phase-separated superconductors with nonvolatile MTS is needed. Here, we show that the In52-Sn48 commercial solder is a phase-separated superconducting composite with two Tc and traps vortices after field cooling. A clear signature of nonvolatile MTS was observed at T = 2.5 K. From specific heat analyses, we conclude that the vortices are mainly trapped in the lower-Tc phase ({\gamma}-phase) after field cooling, which is the evidence that vortex trapping also works on achieving nonvolatile MTS in phase-separated superconducting composites.