Al/Si Ordering In Silicate Minerals
I have a Ph.D. from the Mineral Sciences group of the
Cambridge Earth Sciences Department. The topic of my research was
theoretical and computational study of Al/Si ordering in
aluminosilicates. I have carried out Monte Carlo simulations to
explore the consequences of nearest-neighbour Al/Al avoidance,
ignoring all other interactions, and to carry out fully quantitative
analysis of the effect of low Al concentration on the order/disorder
phase transition. The main result of these simulations is that the
order-disorder transition temperature falls rapidly with decreasing Al
concentration, becoming zero when the concentration falls below a
critical value xc. This
critical value is approximately 0.3 for the tetrahedral framework
structures we have investigated. The simulations have also been used
to tabulate thermodynamic properties such as the order parameter for
the feldspar framework.
You can obtain a copy of my
thesis from the Statslab's FTP site, and
more
information can be found on the
Mineral Sciences home page and on Martin Dove's page on Al/Si
ordering in silicate minerals.