ELECTRONIC AND VIBRATIONAL PROPERTIES OF RB-INTERCALATED MOS2 NANOPARTICLES

Nanoplatelets (diameter about 8 nm) synthesized by laser pyrolysis and bulk powder of MoS2 have been intercalated with Rb to establish the m etallic state. The properties of these powders are investigated by Ram an scattering, X-ray diffraction, transmission electron microscopy and electron spin resonance (ESR). With increasing time of Rb intercalati on the Raman-active interlayer A(1g) mode is observed to red shift in the nanoplatelet sample and blue shift in the micron-size bulk powder sample. In both samples the Rb doping eventually induces a metallic st ate and the Raman signal is lost. A broad ESR line was detected for th e Rb-saturated MoS2 bulk powder sample, also indicating the metallic c haracter. Owing to the small particle size of the nanoplatelets, no br oad line ESR signal was observed for the intercalated nanoplatelets. A low field (ESR) signal was used to starch for superconductivity and a T-c = 6.4 K was observed in the bulk, in good agreement with the lite rature. However, no superconductivity down to 3.5 K was observed in th e nanoplatelet sample.