INTERPLAY OF SUPERCONDUCTING AND INSULATING PHASES IN THE METASTABLE HIGH-RESISTANCE STATES OF THE GA50SB50 ALLOY

Temperature dependences of the resistance R(T) of the alloy GaSb at di fferent stages of its transformation from the high-pressure metastable metallic (M-) phase into the an insulating (I-) phase are measured. A bsolute values of R at these stages span more than eight orders of mag nitude. The superconducting (S-) transition takes place in the low-res istance states at T congruent-to 4.6K. It gives way to a steep increas e of the resistance, i.e. to an insulating transition at the same temp erature in the high-resistance states.