Effect of Diorder on the Peak Effect and Structure of Flux Line Lattice in 2H-NbSe2

TL;DR

This study investigates how disorder influences the melting and structural transitions of flux line lattices in 2H-NbSe2, revealing disorder-induced changes in phase behavior and transition characteristics.

Contribution

It provides new insights into the disorder-dependent behavior of flux line lattices, identifying stepwise disordering and the disappearance of certain features with increased disorder.

Findings

Stepwise disordering of FLL on the upper Peak Effect branch

Disappearance of the Peak Effect features with stronger disorder

Correlation between disorder level and flux liquid phases

Abstract

The effect of disorder on flux line lattice (FLL) melting is studied via the Peak Effect phenomenon. On the upper branch of the Peak Effect curve, where this effect is more robust, we observe a stepwise disordering of the FLL, suggesting two first order transition spanning the Peak Effect region. The lower part of the curve is found to be strongly affected by disorder. Both the branch and the "nose", i.e., the turnaround of the curve, dissapear in systems with stronger disorder and the observed results are consitent with the line seperating a disentangled liquid or a glass from an entangled flux liquid.