Pulverization of the flux line lattice, the phase coexistence and the spinodal temperature of the order-disorder transition in a weakly pinned crystal of Yb$_3$Rh$_4$Sn$_{13}$

TL;DR

This study investigates the complex metastability and phase coexistence during the order-disorder transition in the vortex lattice of a weakly pinned Yb3Rh4Sn13 superconductor, revealing a multi-step transition and a critical point in the phase diagram.

Contribution

It provides new insights into the multi-step nature of the order-disorder transition and the phase coexistence regime in a weakly pinned superconductor, highlighting the termination of the PE line at a critical point.

Findings

Metastability effects are observed in the peak effect region.

The phase coexistence involves ordered and disordered regions.

The PE line terminates at a critical point in the vortex phase diagram.

Abstract

We have studied metastability effects pertaining to the peak effect (PE) in critical current density ($J_c$) via isofield scans in ac susceptibility measurements in a weakly pinned single crystal of Yb$_3$Rh$_4$Sn$_{13}$ ($T_c(0) \approx 7.6 $~K). The order-disorder transition in this specimen proceeds in a multi-step manner. The phase coexistence regime between the onset temperature of the PE and the spinodal temperature (where metastability effects cease) seems to comprise two parts, where ordered and disordered regions dominate the bulk behavior, respectively. The PE line in the vortex phase diagram is argued to terminate at the low field end at a critical point in the elastic (Bragg) glass phase.