<![CDATA[Investigation of the phase boundary of superconducting Pb/Al hybrid macroscopic and mesoscopic structures is conducted and reported. The structures consists of 50 nm thin Al circular disk with 50 nm Pb disk deposited on top of it and 10 nm Ge deposited in between as insulation layer. Radius of the disk is 4 μm for macroscopic and 1,5 μm for mesoscopic structures. Deposition process was carried out with bi-layer lift-off electronic beam lithography technique. The measurements are performed in a 3He bath cryostat with temperature range from below 1 K to less than 7.19 K (Tc of Pb). Current of 5μA is applied to the sample and the R(T) measurement is performed for constant magnetic field H. Measurements are done for several values of magnetic field with a step of 0.1 mT. Field cooled measurements on macroscopic Al disk with diameter 4 μm and 1,5 μm and 50 nm thickness were carried out for reference. Results indicates that Pb strongly screened the field of Al for both macroscopic and mesoscopic samples with Little-Parks oscillation observed for mesoscopic disk. Tc values ofmacroscopic and mesoscopic samples show that superconductivity nucleation is strongly dependant on samplesâ boundary surface.Keywords: Coherence Length, Phase-Boundary, Little-Parks Oscillations.]]>
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