Low-frequency Raman spectroscopy of deuterium to megabar pressures at 77-295 K

Journal Article · Wed Sep 01 04:00:00 EDT 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.5779· OSTI ID:6213596

Hemley, R J; Eggert, J H; Mao, H ^[1]

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1. Geophysical Laboratory and Center for High Pressure Research, Carnegie Institution of Washington, 5251 Broad Branch Road Northwest, Washington, D.C. 20015 (United States)

Rotational and lattice phonon excitations in the Raman spectrum of solid molecular deuterium have been measured from 1.8 GPa to [similar to]200 GPa at 77-295 K to study pressure-induced changes in structural and dynamical properties of the dense solid. Continuous and discontinuous changes in three distinct pressure ranges are observed. At lower pressures ([lt]30 GPa), there is a gradual increase in the linewidth of the [ital S][sub 0](0) band, together with gradually decreasing resolution of the higher-energy [ital S][sub 0](1) and [ital S][sub 0](2) features. At intermediate pressures (60--100 GPa), a change in the pressure dependence and linewidth of [ital S][sub 0](0), and a linewidth and intensity decrease in the [ital E][sub 2[ital g]] phonon band occur. This is interpreted as evidence for a phase transformation in the molecular solid beginning at [similar to]65 GPa (77 K). At the highest pressures ([similar to]160 GPa), abrupt changes in the low-frequency excitations suggest either an expansion of the molecular bond or a change in ordering at the vibron discontinuity. Evidence from the low-frequency spectra for interaction between the deuterium sample and diamond anvil is also examined.

• OSTI ID: 6213596
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:9; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665430* -- Other Topics in Quantum Fluids & Solids-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRYSTALS
DEUTERIUM
HYDROGEN ISOTOPES
ISOTOPES
LATTICE VIBRATIONS
LIGHT NUCLEI
MOLECULAR CRYSTALS
NUCLEI
ODD-ODD NUCLEI
PHASE TRANSFORMATIONS
PRESSURE DEPENDENCE
RAMAN SPECTRA
SOLIDS
SPECTRA
STABLE ISOTOPES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
VERY HIGH PRESSURE