Аннотация
The Tl2Ba2CaCu2O8 (Tl-2212) phase superconductor with critical temperature 110 K, offers a better phase stability, easier synthesis control and more reproducible superconducting properties than Tl2Ba2Ca2Cu3O10 (Tl-2223) with critical temperature 125 K, making it more suitable for systematic studies despite its slightly lower critical temperature. To enhance the critical current density, magnetic nanoparticles with size, l between the coherence length, and the penetration depth, can be added to the Tl-2212 phase, where the particles act as effective flux pinning centers. In this study, 120 nm antiferromagnetic FeF2 nanoparticles were added into Tl2Ba2Ca2Cu2O8(FeF2)x with x = 0 to 0.04 wt.%. The main aim was to investigate the effects of nanosized FeF2 on the Tl-2212 phase formation and critical temperature. X-ray diffraction (XRD) analysis confirmed that a single Tl-2212 superconducting phase was formed in all FeF2 added samples. The non-added sample exhibited a superconducting onset critical temperature (Tc-onset) of 108 K, whereas samples with FeF2 additions of x ≤ 0.03 wt. % retained a relatively high Tc-onset of approximately 100 K, indicating that low FeF2 concentrations have only a minimal effect on the onset of superconductivity. These results demonstrate that FeF2 can be incorporated into Tl-2212 without causing significant disruption to phase formation or the critical temperature provided that the doping level is x ≤ 0.03 wt.%. This suggests that careful FeF2 doping could be a viable addition for optimizing microstructural and textural properties while maintaining high critical temperature.