ELECTRICAL-PROPERTIES OF CU-O MONOLAYERS INTERCALATED INTO CRYSTALLINE GRAPHITE

Electrical properties of Cu-O monolayers intercalated into crystalline graphite have been studied at microwave frequencies (up to 1 GHz) in the temperature range 80-400 K. As the temperature increases above 300 K, the resistance of the starting graphite samples increases because of oxygen desorption. Heating a sample containing intercalated Cu-O la yers results in a transition from the metallic to the semiconducting ( or insulating) state in the 95-130 K interval. At T=8 K, the samples e xhibit microwave absorption typical of superconductors (this effect is not observed at T=260 K). (C) 1997 American Institute of Physics.