Upper critical field, lower critical field and critical current density of FeTe0.60Se0.40 single crystal

TL;DR

This study investigates the superconducting properties of FeTe0.60Se0.40 single crystals, including critical fields and current density, revealing high upper critical fields, anisotropy in lower critical fields, and significant critical current densities.

Contribution

The paper provides detailed measurements of critical fields and current density in FeTe0.60Se0.40, highlighting anisotropic behavior and comparing activation energy with FeAs122 superconductors.

Findings

High upper critical fields (Hc2) observed.

Anisotropy in lower critical field (γ ~ 4).

Critical current density ~10^5 A/cm^2 at 1.8K.

Abstract

The transport and magnetic studies are performed on high quality FeTe0.60Se0.40 single crystals to determine the upper critical fields (Hc2), lower critical field (Hc1) and the Critical current density (Jc). The value of upper critical field Hc2 are very large, whereas the activation energy as determined from the slope of the Arrhenius plots are was found to be lower than that in the FeAs122 superconductor. The lower critical field was determined in ab direction and c direction of the crystal, and was found to have a anisotropy of 'gamma'{=(Hc1//c) / (Hc1//b)} ~ 4. The magnetic isotherms measured up to 12 Tesla shows the presence of fishtail behavior. The critical current densities at 1.8K of the single crystal was found to almost same in both ab and c direction as 1X105 Amp/cm2 in low field regime.