Surface pinning in amorphous ZrTiCuNiBe alloy

TL;DR

This study investigates how surface pinning affects flux lattice dynamics in an amorphous ZrTiCuNiBe superconductor by measuring electromagnetic radiation and proposing a model to analyze pinning effects.

Contribution

It introduces a model for EM radiation from superconductors with non-uniform pinning, linking experimental data to vortex viscosity and pinning parameters.

Findings

Surface pinning significantly influences flux lattice behavior.

The proposed model can reconstruct vortex viscosity and Labush parameters.

Behavior of pinning parameters aligns with collective pinning theory considering thermal fluctuations.

Abstract

We have measured the amplitude and the phase of an electromagnetic (EM) field radiated from superconductor (amorphous ZrTiCuNiBe alloy) in the mixed state due to interaction of the flux lattice with an elastic wave. The results undoubtedly point to an essential contribution of a surface pinning into the flux lattice dynamics. We propose a model that describes radiation of EM field from superconductors with non-uniform pinning. The model allows to reconstruct the viscosity and the Labush parameters from the experimental data. The behavior of the Labush parameter can be qualitatively explained in terms of the collective pinning theory with the allowance of thermal fluctuations.