Abstract
The proton spin-lattice relaxation time T1 of residual stage-3 HNO3-intercalated graphite has been measured as a function of temperature over the range 8310 K. We observe two relaxation times over the temperature range 8180 K and four relaxation times in the range 180310 K. We observe changes in slope at 40, 90, 180, 210, and 250 K. The Fourier transform of the free induction decay consists of three lines: a central peak with two satellites. The angular dependence of the satellites is fitted with a Lorentzian convolution of the spectrum of a conically averaged Pake doublet. This analysis assumes that in one structural phase, pairs of HNO3 molecules hydrogen bond to form a dimer. Interatomic distances in such a molecule conform to a commensurate (7×7)R19.11° orientation with respect to the graphite lattice. The existence of several T1 values requires the existence of a second structural phase in islands separate from the first; this is proposed as (3 × 3) R0° based on the sample stoichiometry.
Original language | English |
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Pages (from-to) | 6148-6155 |
Number of pages | 8 |
Journal | Physical Review B |
Volume | 39 |
Issue number | 9 |
DOIs | |
State | Published - 1 Jan 1989 |
ASJC Scopus subject areas
- Condensed Matter Physics