Prof David Price
Prof David Price
Price's early work was in the field of crystallography and mineralogy. This work created the foundation of his interest in the mineralogy of the deep Earth, and the factors which determine crystal structures. Three notable studies included:
(i) The use of the transmission electron microscope to identify the spinel and beta-phase polymorphs of Mg2SiO4 in shocked meteorites, and the determination of the high strain rate mechanisms of the olivine to spinel, and spinel to beta-phase transformations. This work i ncluded the description of the first natural occurrence of beta-Mg2SiO4, which he named wadsleyite, and which is the major constituent of the upper part (400km to 550km depth) of t he transition zone of the Earth’s mantle.
(ii) The determination of the crystal structure of the as-synthesised silicalite (the pure Si analogue of the zeolite ZSM-5, which is the catalyst that underpins the multimillion-pound petroleum refinement industry).
(iii) The spinel and beta-phase polymorphs of Mg2SiO4 are “spinelloids”, and are polytypes (structures made of the same “modules” but stacked in differing ways), as are the zeolites ZSM-5 and ZSM-11. In an attempt to establish the factors that determined the relative stabilities of polytypic stacking arrangements, Price developed a model of polytypism (and polysomatism) based on the ANNNI and related Ising spin models.
These crystallographic studies led Price to use and develop atomistic simulations to study the energetics and stability of major Earth-forming minerals. Seventeen years ago, Price was the first to use quantum mechanical molecular dynamics methods to study mantle-forming phases, and this led to the first applications of this method to the study of the high P/T elastic and seismic properties of silicates, and which more recently enable his group to reconcile the previously seismically enigmatic D” zone at the base of the mantle (depth ~2600km to 2880km) with the properties of the recently discovered post-perovskite phase. Price has since extended the application of quantum mechanical molecular dynamics methods to the study of the high pressure melting of iron and its alloys, and to the study of the properties of liquid iron under conditions relevant to the Earth’s core.