1209.3586 (Cornelis Jacominus Van Der Beek et al.)

Electron irradiation of Co, Ni, and P-doped BaFe2As2 - type iron-based
superconductors    [PDF]

Cornelis Jacominus Van Der Beek, Sultan Demirdis, Dorothée Colson, F. Rullier-Albenque, Yanina Fasano, Takasada Shibauchi, Yuji Matsuda, Shigeru Kasahara, Piotr Gierlowski, Marcin Konczykowski

High energy electron irradiation is used to controllably introduce atomic-scale point defects into single crystalline Ba(Fe_1-xCo_x)_2As_2, Ba(Fe_1-xNi_x)_2As_2, and BaFe_2(As_1-xP_x)_2. The appearance of the collective pinning contribution to the critical current density in BaFe_2(As_1-xP_x)_2, and the magnitude of its enhancement in Ba(Fe_1-xCo_x)_2As_2, conform with the hypothesis of quasi-particle scattering by Fe vacancies created by the irradiation. Whereas the insignificant modification of the temperature dependence of the superfluid density in Ba(Fe_1-xCo_x)_2As_2 and Ba(Fe_1-xNi_x)_2As_2 points to important native disorder present before the irradiation, the critical temperatures of these materials undergo a suppression equivalent to that observed in the much cleaner BaFe_2(As_1-xP_x)_2. This lends credence to the hypothesis of line nodes of the order parameter (at finite k_{z}) in the former two materials.

View original: http://arxiv.org/abs/1209.3586