MUTUAL CONVERSIONS BETWEEN THE SUPERCONDUCTING AND INSULATING PHASES IN METASTABLE HIGH-RESISTANCE STATES OF THE ALLOY GA50SB50

The temperature dependence of the resistance, R(T), of the alloy GaSb has been measured in various stages of the transition of the metastabl e high-pressure metallic phase into the disordered insulating state. T hese stages span a range of more than eight orders of magnitude in ter ms of the absolute value of R. In the low-resistance states of the sam ple, a superconducting transition is observed at T congruent-to 4.6 K. In the high-resistance states, this transition is replaced by a sharp increase in the resistance, i.e., by a transition to an insulating st ate, at the same temperature.