Characterization of CsC 24 prepared from carbon materials with different graphitization degree

Abstract

Samples of CsC 24 were prepared from carbon materials (derived from petroleum cokes) with different graphitization degree and were characterized by X-ray diffraction (XRD), electron spin resonance (ESR) and Raman spectroscopy. The XRD measurement showed that all the host carbon samples heat treated from 1300 to 2800°C being contacted with CsC 8 planar specimen allowed the intercalation of Cs. Correspondingly, the resulting CsC 24 samples were able to sorb hydrogen molecules, which is a clear evidence of the formation of the nanospace. The broad ESR signal due to conduction electron observed for carbon samples (heat-treatment temperature, HTT above 2200°C) disappeared after intercalation of Cs because of the spin–orbit interaction caused by the intercalated Cs. The Raman G-band of the CsC 24 samples (HTT above 1750°C) shifted from 1584 cm −1 of the host carbon to higher wave number (∼1602 cm −1) in agreement with the reported data for CsC 24. In addition, it was confirmed that the D-band signal disappeared for the CsC 24 samples (HTT above 2000°C).