Compressibility and phonon spectra of the ternary graphite compound KHgC/sub 4/

Journal Article · Tue May 15 04:00:00 EDT 1984 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.29.5947· OSTI ID:6788487

Kim, H J; Mertwoy, H; Koch, T; Fischer, J E; McWhan, D B; Axe, J D

Room-temperature measurements of the c-axis compressibility and longitudinal phonon dispersion (qparallelc) are reported for the stage-1 ternary graphite compound KHgC/sub 4/. Both the direct measurement and the small-q slope of the LA branch give K = 4.4 +- 0.1 x 10/sup -12/ cm/sup 2//dyne, twice the value for the stage-1 binary KC/sub 8/. Phonon energies are generally lower than in KC/sub 8/, and the dispersion is well represented by a second-neighbor force-constant model based on the Herold four-layer repeat unit, although the experimental evidence for one of the predicted optic branches is tenuous. All of the results point to much softer interlayer interactions in KHgC/sub 4/ relative to KC/sub 8/, consistent with other experiments which indicate that the c-axis charge distribution in the ternary is more metallic (or less ionic) relative to the corresponding binary compound.

• Research Organization: Physics Department and Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104
• OSTI ID: 6788487
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 29:10; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALI METAL COMPOUNDS
CARBIDES
CARBON
CARBON COMPOUNDS
CLATHRATES
COHERENT SCATTERING
COMPRESSIBILITY
DATA
DIFFRACTION
DISPERSION RELATIONS
ELASTIC SCATTERING
ELEMENTS
EXPERIMENTAL DATA
INELASTIC SCATTERING
INFORMATION
INTERACTIONS
LAYERS
MECHANICAL PROPERTIES
MEDIUM TEMPERATURE
MERCURY COMPOUNDS
NEUTRON DIFFRACTION
NONMETALS
NUMERICAL DATA
PHONONS
POTASSIUM CARBIDES
POTASSIUM COMPOUNDS
PYROLYTIC CARBON
QUASI PARTICLES
SCATTERING