Superconducting properties of Al wires deposited on SrTiO3 and LaAlO3/SrTiO3 substrates

Abstract We report the superconducting properties of Aluminium (Al) wires deposited on different substrates. The substrates selected are the band insulator of SrTiO3 (STO) and the 2DEG system of LaAlO3/SrTiO3 (LAO/STO). Al wires were prepared from the respective films using focused ion beam assisted milling. A significant reduction in the superconducting transition temperature was observed with respect to a control Al film which was deposited on SiO2/Si substrate. The superconducting transition temperature of Al wire on STO substrate is 0.36 K, while that of LAO/STO substrate is 0.66 K. The temperature dependent critical current follows the classical Ginzburg-Landau formulation but with slightly varying exponent values compared to the value of 3/2 corresponding to a film in the clean limit.