Anisotropic low field behavior and the observation of flux jumps in CeCoIn5

TL;DR

This study investigates the magnetic properties of CeCoIn5, revealing flux jumps, anisotropic critical fields, and low critical currents, contributing to understanding its superconducting behavior at low temperatures.

Contribution

It provides new insights into flux jumps, anisotropic magnetic responses, and critical current values in CeCoIn5, a heavy fermion superconductor.

Findings

Flux jumps occur in a restricted temperature range and disappear below 1.7 K.

Magnetization loops are asymmetric, indicating surface and geometrical pinning effects.

The lower critical field Hc1 is linear with temperature and anisotropic.

Abstract

The magnetic behavior of the heavy fermion superconductor CeCoIn5 has been investigated. The low field magnetization data show flux jumps in the mixed state of the superconducting phase in a restricted range of temperature. These flux jumps begin to disappear below 1.7 K, and are completely absent at 1.5 K. The magnetization loops are asymmetric, suggesting that surface and geometrical factors dominate the pinning in this system. The lower critical field (Hc1), obtained from the magnetization data, shows a linear temperature dependence and is anisotropic. The calculated penetration depth is also anisotropic, which is consistent with the observation of an anisotropic superconducting gap in CeCoIn5. The critical currents, determined from the high field isothermal magnetization loops, are comparatively low (around 4000 A/cm2 at 1.6 K and 5 kOe).