AC/DC Susceptibility of the Heavy-Fermion Superconductor CePt3Si under Pressure

TL;DR

This study explores how pressure affects the superconducting and antiferromagnetic properties of CePt3Si, revealing a complex interplay and inhomogeneity effects near the critical pressure where antiferromagnetism vanishes.

Contribution

It provides detailed measurements of ac and dc susceptibilities under pressure, highlighting the relationship between antiferromagnetism and superconductivity in CePt3Si.

Findings

Tc decreases with pressure, especially near Pc

Transition widths narrow near Pc, indicating inhomogeneity effects

Meissner fraction increases above Pc, suggesting antiferromagnetism influences superconductivity

Abstract

We have investigated the pressure dependence of ac and dc susceptibilities of the heavy-fermion superconductor CePt3Si (Tc= 0.75 K) that coexists with antiferromagnetism (TN = 2.2 K). As hydrostatic pressure is increased, Tc first decreases rapidly, then rather slowly near the critical pressure Pc = 0.6 GPa and shows a stronger decrease again at higher pressures, where Pc is the pressure at which TN becomes zero. A transition width and a difference in the two transition temperatures defined in the form of structures in the out-of-phase component of ac susceptibilities also become small near Pc, indicating that a double transition observed in CePt3Si is caused by some inhomogeneous property in the sample that leads to a spatial variation of local pressure. A sudden increase in the Meissner fraction above Pc suggests the influence of antiferromagnetism on superconductivity.