Nonlogarithmic magnetization relaxation in HTSC

TL;DR

This study investigates magnetic flux relaxation in YBCO superconductors near the transition point, revealing vortex dynamics akin to TAFF and validating Zeldov's creep model for describing magnetization behavior.

Contribution

First experimental observation of vortex dynamics similar to TAFF in weak fields in YBCO, and validation of Zeldov's creep model for magnetization relaxation.

Findings

Vortex dynamics similar to TAFF observed in weak fields.

Zeldov's creep model successfully describes magnetization behavior.

Normalized relaxation rate estimated within the model.

Abstract

An experimental study of low density captured magnetic flux dynamics in YBCO single crystal samples near the superconducting phase transition point has been performed. Vortex dynamics similar to thermally assisted flux flow regime (TAFF) has been observed for the first time in such weak fields. It will be shown that Zeldov's thermoactivated creep model successfully describes the behavior of the magnetization in the YBCO single crystals in our experiments. Within the framework of this model the estimation of normalized relaxation rate was made.