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The series of DyF3 nanoparticles samples are synthesized by the hydrothermal treatment in autoclave at 140°C, 160°C, 200°C and 230°C for 24 h. The samples are characterized by X-ray powder...

Interest to studies of gallium alloys increased recently in relation totheir prospective applications for self-healing superconducting connectionsand wires. Special attention is focused on superconductive properties ofnanostructured alloys. In the present work we studied the ac susceptibilityof a porous glass/Ga-In-Sn nanocomposite within the temperature range from1.9 to 8 K at bias fields up to 5 T. Two superconducting phase transitionswere revealed with temperatures of 5.6 and 3.1 K. Phase diagrams werecreated. Positive curvature of the parts of critical lines was demonstratedand treated within the framework of a proximity effect model. Vortexactivation barriers were found from shifts of the maxima of the imaginaryparts of susceptibility with changing the ac frequency. A bend was shown onthe field dependence of the activation barriers. Keywords: Ga-In-Sn triple alloy, nanocomposite, superconductivity, magnetometry.\

For applications of nanolattices in low-temperature nanoelectronics, the inter-unit space can be filled with superconducting metallic alloys. However, superconductivity under nanoconfinement is expected to be strongly affected by size-effects and other factors. We studied the magnetic properties and structure of the Ga-Sn eutectic alloy within regular nanopores of an opal template, to understand the specifics of the alloy superconductivity. Two superconducting transitions were observed, in contrast to the bulk alloy. The transitions were ascribed to the segregates with the structures of tetragonal tin and a particular gallium polymorph. The superconducting-phase diagram was constructed, which demonstrated crossovers from the positive- to the common negative-curvature of the upper critical-field lines. Hysteresis was found between the susceptibilities obtained at cooling and warming in the applied magnetic field.