Controlled superconductivity of a semiconductor-superconductor eutectic composition

The electrical properties of a GaSb-V2Ga5 eutectic composition have been studied. This system comprises long oriented whiskers of a superconducting V2Ga5 phase formed by directed crystallization in a semiconducting GaSb matrix. The properties of samples can be controlled by varying the angle between the directions of electric current and whiskers. The observed features of the temperature dependence of the resistivity and the possibility of controlling the properties of the eutectic system are explained by the formation of discrete superconducting regions comprising linked Josephson junctions of the superconductor-semiconductor-superconductor type (S-Sm-S-Sm-S‖), whiskers consisting of linked microscopic bridges (S-S′-S-S′-S‖), and infinite clusters comprising combinations of the above two components (S-S′-S-Sm-S-S′-S‖).