Low-temperature crystal and band electronic structure of organic metals, α- (BETS)2I3 and (MeBr-DCNQI)2Cu

Room temperature and low-temperature(13K) crystal and band electronic structures of α- (BETS)2I3 (BETS=bis(ethylenedithio)tetraselenafulvalene) were examined by using a newly developed X-ray crystal structure analysis system based on imaging plate(IP) equipped with a closed-cycle helium refrigerator. The X-ray low-temperature studies of (MeBr-DCNQI)2Cu (DCNQI=dicyanoquinonediimine) by using IP system have revealed that the structure change mainly associated with the charge ordering of Cu occurs discontinuously at TMI but the structure change related to the development of CDW on DCNQI stacks is continuous.