Magneto-transport properties of (Cu)x/CuTl-1223 nanoparticles-superconductor composites.

Graphical abstract Highlights • Temperature dependent magneto-transport properties of (Cu) x /CuTl-1223 composites were performed. • Improvement in infield superconductivity was observed after inclusion of Cu nanoparticles. • Optimum content level of Cu nanoparticles in (Cu) x /CuTl-1223 composites was found x = 1.0 wt%. • M-H loops indicated mixed superconducting and ferromagnetic behaviour up to 90 K in all samples. Abstract Copper (Cu) nanoparticles and Cu 0.5 Tl 0.5 Ba 2 Ca 2 Cu 3 O 10−δ (CuTl-1223) superconducting phase were synthesized by sol-gel and solid-state reaction, respectively. These metallic Cu nanoparticles were added in CuTl-1223 superconducting matrix to get (Cu) x /CuTl-1223; x = 0–4.0 wt% nanoparticles-superconductor composites and their temperature dependent magneto-transport properties were studied. The zero-field-cooled (ZFC) and field-cooled (FC) temperature dependent magnetization (M-T) measurements of (Cu) x /CuTl-1223 samples showed an increase in transition temperature and in amplitude of diamagnetic signal after the inclusion of Cu nanoparticles in the host CuTl-1223 matrix. The improvement in these magneto-transport properties can be attributed to the increase in number of efficient pinning centres in CuTl-1223 matrix after addition of Cu nanoparticles. Magnetization hysteresis (M-H) loops were obtained at various operating temperatures from which the magnetization critical current density (J c) was estimated using Bean's critical state model. M-H loops indicated the combined superconducting and ferromagnetic behaviour up to 90 K in all (Cu) x /CuTl-1223 samples. Improvement in J c could also be due to increase in number of pinning centres with addition of Cu nanoparticles in CuTl-1223 matrix. Maximum improvement in magneto-transport properties of (Cu) x /CuTl-1223 samples was observed for x = 1.0 wt%, which had specified the optimum content level of Cu nanoparticles in CuTl-1223 phase. [ABSTRACT FROM AUTHOR]