Structures of vortex in Co-doped BaFe2As2 iron superconductors with different doping level by scanning Hall probe microscopy

Abstract

The 122 iron arsenide unconventional superconductors are part of a new class of iron-based superconductors. Co-doped BaFe_2xCo_xAs₂ (Ba-122) iron superconductors sample have been examine by scanning Hall probe microscopy (SHPM) technique to find out the magnetic properties of Ba-122 . Has been completed the evolution of profiles of vortices which has well isolated and it is as function of temperature, then utilized suitable technique to extract the temperature depending on penetration depth, .So, this allowed to deduce the temperature dependent on density of superfluid and it has been compared with α-model consequences for a (2-band) of superconductor. When the superfluid density for the BaFe_2xCoxAs₂ (Over D x= 0.113) sample. As result, the two gap -model has been fitted to the data with Δ₁=4.25kT_c, Δ₂=1.92kT_c , =0.708, ₁=0.293 then a₂=1. However, When values of  for the BaFe_2-xCo_xAs₂ (Over D x= 0.075) sample. Result of the superfluid density for BaFe_2-xCo_xAs₂ with parameters are (Δ₁=3.9k, Δ₂=1.6k), =0.615 for Δ₁, and =0.237, =1. Suitable parameters produce refer into the symmetry of the order parameter at hole pockets with the electron, and then the relative supports of the bands to the density of superfluid in the iron-based crystals.