TEMPERATURE-DEPENDENT RAMAN-SPECTRA AND ANOMALOUS RAMAN PHENOMENON OFHIGHLY ORIENTED PYROLYTIC-GRAPHITE

The Stokes and anti-Stokes Raman spectra of the pristine and ion-impla nted highly oriented pyrolytic graphite (HOPG) are reported. For all R aman bands, noticeable frequency shifts are observed in the different temperature of samples. The anomalous Raman phenomenon (ARP) indicates that some modes occurring on the Stokes and anti-Stokes sides have di fferent frequencies for HOPG. The data suggest that the ARP is closely related with the excitation wavelength (lambda) dependence of Raman b ands of the graphite. According to the temperature effect and the ARP, we assign and verify some modes of HOPG, and predict some new results .