-
Recovery and characterisation of high-pressure phases in the systems H2O ¿ NH...
The objective of this experiment is to characterise four particular high-pressure polymorphs of various hydrates discovered by us in recent years during work carried out using... -
Phase behaviour of methane clathrate under conditions relevant to Titan's int...
Methane clathrates are likely to be an important constituent of icy satellite interiors and a source of methane in the atmosphere of Saturn's giant satellite Titan. There is... -
Rheological properties of ice-rock mixtures
The large icy satellites of Jupiter and Saturn are denser than pure water-ice and so must contain "rock" contaminants that can greatly affect each moon's geological (and hence... -
Cation substitution in synthetic meridianiite (MgSO4.11D2O): phase behaviour ...
MgSO4.11H2O (MS11) is the most highly hydrated phase in the binary MgSO4¿H2O system. Whilst lower hydrates in this system have end-member analogues containing alternative... -
Compression of meridianiite (MgSO4.11D2O) single crystals to 5 kbar
We propose to carry out single crystal diffraction measurements of the most hydrated MgSO4 compounds, meridianiite, using a thin-walled TiZr gas cell on SXD up to 5 kbar. These... -
Single-crystal analysis of disorder in deuterated and protonated mirabilite
Mirabilite (Na2SO4.10H2O) is relevant to many areas of geology, planetary science, and even the construction industry. It occurs naturally in evaporite deposits, and even as... -
Recovery and characterisation of high-pressure phases in the systems H2O ¿ NH...
The objective of this experiment is to characterise four particular high-pressure polymorphs of various hydrates discovered by us in recent years during work carried out using... -
Structure, incompressibility and thermal expansion of ammonia dihydrate II
The structure and properties of the high-pressure phase of ammonia dihydrate, ADH-II, have been challenging to determine. However, the structure has been solved recently by... -
High pressure behaviour of sulfuric acid tetrahydrate
Our previous work on sulfuric acid tetrahydrate (SAT) identified a monoclinic high-pressure polymorph, which forms at 5.35 kbar when the tetragonal low-pressure phase is warmed... -
Cation substitution in synthetic meridianiite (MgSO4.11H2O): site distributio...
MgSO4.11H2O (MS11) is the most highly hydrated phase in the binary MgSO4¿H2O system. Whilst lower hydrates in this system have end-member analogues containing alternative... -
Characterising new high-pressure phases of ammonia monohydrate
Over the past two years I have carried out high-pressure surveys of the ammonia monohydrate (AMH) phase diagram using a Paris-Edinburgh press mounted on the D20 beam-line at the... -
The phase transitions in epsomite (MgSO4.7D2O)
Epsomite is known to undergo a series of phase transitions up to 3 GPa at room temperature, a pressure regime which is of relevance to the interiors of icy planetary bodies,... -
Behaviour of hexamethylenetetramine hexahydrate to 5 GPa
The title compound, more succinctly referred to as HMT-hydrate, is a rare example of a water-framework zeolite structure with an organic guest molecule hydrogen bonded to the... -
Equation of state of ice VI
Ice VI is likely to be a major mantle mineral in the interiors of large icy moons in our solar system, and in large icy extrasolar planets. It is also a common accessory phase... -
Hydrogen-bond ordering in hexamethylenetetramine hexahydrate as a function of...
The title compound, more succinctly referred to as HMT-hydrate, is a rare example of a water-framework zeolite structure with an organic guest molecule hydrogen bonded to the... -
The Grüneisen and Anderson-Grüneisen parameters of mirabilite (Na2SO4.10D2O)
Sodium sulfate decahydrate (mirabilite) may be an important rock-forming mineral in the outer solar system, comprising a large fraction of the mantles of Jupiter's icy moons; it... -
Phase behaviour of methane clathrate under conditions relevant to Titan's int...
Methane clathrates are likely to be an important constituent of icy satellite interiors and a source of methane in the atmosphere of Saturn's giant satellite Titan. There is... -
Thermal expansion and simultaneous Raman spectroscopy of methanol ammoniates,...
We have recently determined the structures of methanol-monoammoniate, and Me-hemiammoniate from neutron powder data. These are found to have different degrees of C-H...O... -
Crystal structure and thermal expansion of acetylene (C2D2)
Acetylene is produced in great abundance in the solar system wherever carbonaceous solids are exposed to energetic radiation. It has been the subject of several studies,... -
Thermoelastic properties of ammonium sulfate, (ND4)2SO4, and the P-T dependen...
Ammonium sulfate exhibits a first-order phase transition upon cooling through ~ 224 K at room pressure, from a paraelectric to a ferroelectric crysta. There are outstanding...