Thermo-magnetic history effects in the vortex state of YNi_2B_2C superconductor

TL;DR

This study investigates the anisotropic thermo-magnetic history effects in the vortex state of YNi2B2C superconductor, revealing complex flux line lattice behaviors and history-dependent magnetization phenomena.

Contribution

It provides new insights into the anisotropic flux line lattice behavior and the history dependence of vortex matter in YNi2B2C, highlighting superheating/supercooling effects.

Findings

Distinct five-quadrant magnetic isotherms indicating anisotropic flux line lattice behavior

Observation of peak effect and second magnetization peak with different hysteresis loop characteristics

History dependence explained by superheating/supercooling across a first-order-like phase transition

Abstract

The nature of five-quadrant magnetic isotherms for is different from that for in a single crystal of YNi2B2C, pointing towards an anisotropic behaviour of the flux line lattice (FLL). For, a well defined peak effect (PE) and second magnetization peak (SMP) can be observed and the loop is open prior to the PE. However, for, the loop is closed and one can observe only the PE. We have investigated the history dependence of magnetization hysteresis data for by recording minor hysteresis loops. The observed history dependence in across different anomalous regions are rationalized on the basis of su-perheating/supercooling of the vortex matter across the first-order-like phase transition and possible additional effects due to annealing of the disordered vortex bundles to the underlying equilibrium state.