Kristallogrpahie & Geomaterialforschung
.
Crystallography and Geomaterials Research
group – Current projects
Local oder and physical properties in Olivine
Funded by the EXC
`The Ocean Floor - Earth's Uncharted Interface'
PhD student: MSc
Christin Wiggers
The solid solution series of Olivine (FexMg1-x)2SiO4
(0 < x < 1) and compounds with olivine structure are
considered as a natural CO2 storage material, a
source of alkalinity during enhanced weathering and as a
potential cathode material. Olivine with a composition of Fe0.1Mg0.9SiO4
is the dominant phase of the upper mantle and one of the most
abundant minerals on Earth. Members of the mineral group are
present in igne-ous and metamorphic rocks of basaltic origin
and a common constituent of chondritic and achon-dritic
meteorites.
In the crystal structure, the divalent cations are distributed over two symmetrically independent octahedral layers. Additionally, 1/8 of the tetrahedral sites between the octahedra are occupied by Si4+. The overarching goal of this project is to understand possible local ordering principles in olivine and their relation to observable physical properties. It has been shown that different thermal hisotries of the sample material influence the cation partioning – an average structural propertie. However, we expect that correlations that presist only locally are much more sensitive to such envirnmental changes. Therefore, we aim at observing and manipulating different degrees of local order and use these as a more precice and probe of the sample history.
In the crystal structure, the divalent cations are distributed over two symmetrically independent octahedral layers. Additionally, 1/8 of the tetrahedral sites between the octahedra are occupied by Si4+. The overarching goal of this project is to understand possible local ordering principles in olivine and their relation to observable physical properties. It has been shown that different thermal hisotries of the sample material influence the cation partioning – an average structural propertie. However, we expect that correlations that presist only locally are much more sensitive to such envirnmental changes. Therefore, we aim at observing and manipulating different degrees of local order and use these as a more precice and probe of the sample history.