High-pressure studies of melamine
- UNLV
We performed the first high-pressure study of melamine using X-ray Raman spectroscopy (XRS) up to -17 GPa in a diamond anvil cell at ambient temperature. We utilized the 16 ID-D undulator beamline at the Advanced Photon Source for the X-ray source. The observed diminishment of the 1s {yields} {pi}* peak as well as other changes in the XRS spectra with pressure suggest the possibility of intra- and inter-molecular bonding changes due to two phase changes in the investigated pressure range or hybridization changes of atomic orbitals in the material with pressure. We also performed a complementary X-ray powder diffraction study of neat melamine up to 24 GPa observing at least two phase transitions with pressure. Pressure cycling indicated that the phase transitions were reversible. Density-functional theory calculations performed on the system at ambient and low pressure show a high level of agreement with the experiments.
- Research Organization:
- Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 1002328
- Journal Information:
- High Pressure Res., Journal Name: High Pressure Res. Journal Issue: (1) ; 03, 2010 Vol. 30; ISSN 0895-7959; ISSN HPRSEL
- Country of Publication:
- United States
- Language:
- ENGLISH
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