High pressure studies on RuIn3 single crystal.

Temperature- and pressure-dependent electrical resistivity studies have been carried out on RuIn(3) single crystal in the 4-300 K range at various pressures between 0 and 5 GPa. While intrinsic semiconducting behaviour is inferred at higher temperatures above 275 K, the low temperature resistivity is primarily dictated by impurity effects. An insulator to metal transition is observed in the low temperature regime around ∼ 1.2 GPa pressure. Band structure calculations show a monotonic decrease of energy gap from a value of 0.222 eV at 0 GPa to 0.167 eV at 8 GPa with increasing pressure, consistent with the experimental findings.