Superconductivity and spin-glass like behavior in system with Pd sheet sandwiched between graphene sheets

TL;DR

This study reveals that Pd-metal graphite exhibits superconductivity at 3.63 K and displays spin-glass-like magnetic behavior due to disordered nanographite regions, combining superconductivity with complex magnetic phenomena.

Contribution

It demonstrates the coexistence of superconductivity and spin-glass-like behavior in Pd-MG, highlighting the role of disordered nanographites in magnetic properties.

Findings

Superconducting transition at 3.63 K in Pd sheets.

Spin-glass-like relaxation observed below T_c.

Antiferromagnetic correlations with negative Curie-Weiss temperature.

Abstract

Pd-metal graphite (Pd-MG) has a layered structure, where each Pd sheet is sandwiched between adjacent graphene sheets. DC magnetization and AC magnetic susceptibility of Pd-MG have been measured using a SQUID magnetometer. Pd-MG undergoes a superconducting transition at $T_{c}$ ($= 3.63 \pm 0.04$ K). The superconductivity occurs in Pd sheets. The relaxation of $M_{ZFC}$ (aging), which is common to spin glass systems, is also observed below $T_{c}$. The relaxation rate $S(t)$ shows a peak at a characteristic time $t_{cr}$, which is longer than a wait time $t_{w}$. The irreversibility between $\chi_{ZFC}$ and $\chi_{FC}$ occurs well above $T_{c}$. The susceptibility $\chi_{FC}$ obeys a Curie-Weiss behavior with a negative Curie-Weiss temperature ($-13.1 \leq \Theta \leq -5.4$ K). The growth of antiferromagnetic order is limited by the disordered nature of nanographites, forming spin glass-like behavior at low temperatures in graphene sheets.