X-ray radiation effects on the electrical conduction of CuIr2S4 in the insulating phase

Abstract Effects of X-ray radiation on the electrical resistance were examined for the insulating phase of spinel compound CuIr 2 S 4 . We found that the resistance decreases by more than five decades by irradiation at 8.5 K . In the X-ray diffraction, the extinction of superstructure reflections was observed at the same time. The X-ray-induced conductance is deduced to result from the destruction of Ir 4+ dimers formed in the insulating phase.