Abstract
In this study, collective excitations of liquid indium are studied just above the melting point at different pressures (1.7 GPa, 240 °C; 3.0 GPa, 300 °C; 4.0 GPa, 360 °C). The pressures and temperatures are achieved by the use of an externally heated diamond anvil cell. Clear evidence for the existence of propagating modes is observed from the dynamical structure factor at constant momentum transfer (Q) up to about 18 nm−1. The reason for the observed high elastic-scattering background is identified, and its effects on the determination of elastic properties such as viscosity are discussed.
Acknowledgements
The use of the Advanced Photon Source was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The high pressure devices in the research were supported by NSF grant no. 0738852 (to G.S.). The electron microscopy was accomplished at the Electron Microscopy Center for Materials Research at the Argonne National Laboratory, a US Department of Energy, Office of Science Laboratory operated under contract no. DE-AC02-06CH11357 by UChicago Argonne, LLC. We would like to thank R.E. Cook of ANL for the help with using the electron microscope and B. Brajuskovic of APS for providing .
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