Flux dynamics in NdO1-xFxFeAs bulk sample

TL;DR

This study investigates the flux dynamics and critical states in NdO1-xFxFeAs bulk superconductors using multi harmonic magneto-dynamic experiments, revealing insights into their flux behavior and dimensionality.

Contribution

The paper provides new experimental data on flux dynamics in NdO1-xFxFeAs, including the measurement of the irreversibility line and analysis of flux dimensionality, using third harmonic ac susceptibility.

Findings

Irreversibility line determined from third harmonic signals

Flux dynamic behavior characterized by critical states

Flux dimensionality analyzed in the sample

Abstract

We present data of multi harmonic magneto-dynamic experiments. In particular, we performed ac magnetic susceptibility experiments on layered pnictide-oxide quaternary compound NdOFeAs doped with fluorine. The experiments allow measure the critical temperature and probe the flux dynamic behavior using the third harmonic component of the ac susceptibility of a NdF0.16FeAsO0.84 bulk sample as a function of temperature and frequency of the applied ac magnetic fields. Measured signals are connected with the non-linear superconducting flux dynamic behavior and are characterized by a flux critical states sustaining a superconducting critical current. In this framework the irreversibility line that describes the stable superconducting state has been extracted from the onset of the third harmonic signal vs. frequency. Finally we present also the analysis of the flux dynamic dimensionality in the investigated sample.