MOLECULAR-DYNAMICS OF NITRIC-ACID INTERCALATED IN GRAPHITE

This paper presents measurements of the NMR line shape and spin-lattice relaxation time of 2H in deuterated nitric acid intercalated in graphite. Evidence is obtained that a regular network of hydrogen bonds is established in the nitric acid layers. By comparing NMR data for both 1H and 2H in the free and intercalated nitric acid, the role of the decomposition process of HNO3 in the -25°C transition is put into evidence. Diffusional and rotational motions in the HNO3 layers, both below and above the transition, are characterized. The decomposition process markedly influences the molecular dynamics in the layers above the transition. Moreover, it seems related to the charge transfer process between carbon layers and intercalated acid, i.e., with the basal conductivity of graphite. We also discuss the problem of assigning a stoichiometric formula to the nitric acid intercalation compounds of graphite. © 1979 American Institute of Physics.