Anisotropy in vortex phase diagram and the pinning force density in the basal plane of YNi_2B_2C

TL;DR

This study investigates the anisotropic behavior of flux line lattice and pinning forces in YNi_2B_2C, revealing how magnetic field orientation affects vortex order and critical current density decay.

Contribution

It provides new insights into the anisotropic vortex phase diagram and pinning mechanisms in YNi_2B_2C, highlighting the relationship between lattice symmetry and flux line order.

Findings

Peak effect observed for all orientations

FLL order varies with magnetic field direction

Crossover from weak to weaker pinning regime identified

Abstract

We present magnetic field dependence of the critical current density from dc-magnetization measurements concerning the anisotropic behavior of flux line lattice (FLL) in a single crystal of YNi_2B_2C. The peak effect (PE) phenomenon is observed for all crystallographic orientations, but the second magnetization peak (SMP) anomaly is observed only for H//a. Our study reveals that the FLL obtained when H//[100] is better ordered within the basal plane. However, the FLL for H// c is found to be even more ordered than that for H//[110]. The perfect square symmetry of the FLL for H//c is perhaps responsible for promoting the realization of the best spatial order of the FLL prior to the onset of PE, indicating a correlation between the crystalline lattice and the FLL. We have also found a change over in the power law governing the decay of the critical current density which is identified as a crossover from weak to weaker pinning regime in the phase diagram.