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Introduction

Many processes that are specific to certain mineral surfaces can often only be understood if the atomic and electronic structure of these surfaces and, consequently, their reactivity are determined at an atomic or molecular scale. One such example is the oxidation mechanism on sulfide surfaces that can be only insufficiently described by using wet chemical methods. Only the combination of surface sensitive techniques such as x-ray photoelectron spectroscopy (XPS), imaging methods that work at the molecular scale (STM and AFM) and computer simulations that evaluate the electronic structure at the subatomic level was able to explain the fundamental difference in the oxidation mechanism between different sulfides, e.g., galena, pyrite, and pyrrhotite.

A very different example are crystal growth mechanism that are of technical importance, e.g., the buildup of scale in offshore pipes and wells. One goal for mineral surface studies in this field is to be finally able to design growth inhibitors that are most efficient and very specific to certain minerals and mineral groups. However, even crystal growth mechanisms without inhibitors that are specific to certain surfaces and growth conditions could not be described by direct observations until recently. The example presented in this paper is the self-inhibition of spiral growth on some sulfate surfaces that was resolved by applying AFM in-situ experiments in a fluid cell and modelling island growth using empirical potential models.


next up previous
Next: Oxidation and metal adsorption Up: The reactivity and crystal Previous: The reactivity and crystal
Karsten Knorr
1998-09-22