Kate Wright: Research
My research uses a combination of classical and ab initio simulation methods to understand the nature of microscopic defects in minerals and their influence on macroscopic behaviour
Current Research Projects:
Hydrogen incorporation in NAMs
Figure 1 shows two different configurations for hydrogen in the forsterite structure. (a) adjacent to a magnesium vacancy; and (b) surrounding a silicon vacancy in the "hydrogarnet" configuration.
Large amounts of water could be present as hydrogen defects in the nominally anhydrous minerals (NAMs) of the Earth’s mantle such as olivine and pyroxenes. Research as into the modes of H defect incorporation as a function of mineral chemistry is being undertaken using both classical and ab initio methods.
Modelling of dislocation cores in complex ionic solids
Collaborator: Dr Andrew Walker, University College London.
Figure 2 shows a screw dislocation in MgO
Dislocations are present in all crystalline maeterials and control deformation behaviour. In this study we are investigating the interaction of vacancy and impurity defects with dislocations in MgO.
Crystal chemistry of sphalerite (ZnS)
Sphalerite is the major source of zinc metal but contains impurities such as iron, cadmium and manganese. Studies using a combination of ab initio and classical potential methods are providing insights into the mechanisms of impurity incorporation and their influence on local structure
Metal incorporation in Jarosite [KFe3(SO4)2(OH)6]
Collaborator: Dr Karen Hudson-Edwards, Birckbeck College, London
Figure 3 shows synthetic Pb- jarosite after dissolution at ph3 (Smith et al. Chem. Geol. 229, 344. 2006)
Members of the jarosite group of minerals are found in a wide variety of environments, including acid mine dumps, saline lakes and in Martian soils. They are also used in metallurgical processes to remove unwanted iron and improve metal concentrates. We are investigating the mechanisms of toxic element incorporation in jarosites and the influence of such elements on mineral stability.
