Knight Shift and Nuclear Quadrupolar Interaction in Alkali-Graphite Intercalation Compounds

Abstract

In order to get more information about the electronic structure of Alkali-Graphite Intercalation Compounds, a number of experiments have recently been performed such as electron spectroscopy, NMR on the carbon nucleus, electronic specific heat or positron annihilation [1-4]. In most cases, the experimental results have been discussed with respect to the well-known properties of pristine graphite. Application of the NMR method to the intercalant nuclei, however, offers complementary information by comparison with the properties of the respective alkali metals. Due to the anisotropy of these compounds it is of particular interest to investigate the orientation dependence. In this paper NMR measurements on powder samples as well as on samples of Highly Oriented Pyrolytic Graphite (HOPG) intercalated with Cs and Li are reported. Earlier measurements using powder samples have already been reported by CARVER [5] and by CONRAD and ESTRADE [6].