| dc.description.abstract | We study the proximity effect between the ferromagnetic Ni nanoparticles (NPs) and superconducting In NPs. The In100-XNiX nanocomposites are prepared by mixing two NPs with different mass ratio but constant packing fraction. The NPs are both prepared using thermal evaporation method and the mean diameters of In and Ni NPs were determined by the XRD patterns, where are 13.9 nm and 3.1 nm, respectively.
To study the influence of proximity effect on the superconducting parameters, we measured the magnetic AC susceptibility χ’ of the nanocomposites. By fitting χ’(T) to the Scalapino’s expression, the transition temperature TC and the mean penetration depth are obtained. The penetration depth increases with the increasing mass percentage of Ni NPs, but the TC doesn’t decrease but keeps constant at Ni NPs content up to 45%.
In the other hand, the DC magnetization M were measured at several selected temperatures. For the In NPs, the paramagnetic M(H) curves are observed above TC, while the hysteresis arose by the geometric barrier are observed below TC. The inverted hysteresis, where the remanent magnetization of the reversal curve from the loop 2 is smaller than the initial value from loop 1, appears in low Ni mass ratio, and the enhancement of the superconducting diamagnetic magnetization are found in In80Ni20, In75Ni25, and In55Ni45.
| en_US |