5 papers
Nuclear Spin Crossover in Dense Molecular Hydrogen
Thomas Meier, Dominique Laniel, Miriam Pena-Alvarez +6
The laws of quantum mechanics are often tested against the behaviour of the lightest element in the periodic table, hydrogen. One of the most striking properties of molecular hydro…
The raman signal of a hindered rotor
Peter I. C. Cooke, Ioan B. Magdǎu, Miriam Peña-Alvarez +6
We present a method for calculation of Raman modes of the quantum solid phase I solid hydrogen and deuterium. We use the mean-field assumption that the quantised excitations are lo…
The Observed Vibron Shift in Helium-Hydrogen Mixtures are due to Quantum Nuclear and Localisation Effects, not bonding
Sam B Ramsey, Miriam Pena-Alvarez, Graeme J Ackland
The vibrational frequency of hydrogen molecules has been observed to increase strongly with He concentration in helium hydrogen fluid mixtures. This has been associated with He-H i…
On the Reactivity of Hydrogen-Helium and Hydrogen-Nitrogen at High Pressures
Robin Turnbull, Mary-Ellen Donnelly, Mengnan Wang +6
Through a series of Raman spectroscopy studies, we investigate the behaviour of hydrogen-helium and hydrogen-nitrogen mixtures at high pressure across wide ranging concentrations.…
Graphene under direct compression: stress effects and interlayer coupling
Elena del Corro, Miriam Pena-Alvarez, Michal Mracko +4
In this work we explore mechanical properties of graphene samples of variable thickness. For this purpose, we coupled a high pressure sapphire anvil cell to a micro-Raman spectrome…