文章基本信息

标题：Adatom Fe(III) on the hematite surface: Observation of a key reactive surface species
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作者：Carrick M. Eggleston ; Andrew G. Stack ; Kevin M. Rosso 等
期刊名称：Geochemical Transactions
电子版ISSN：1467-4866
出版年度：2004
卷号：5
期号：2
页码：1-8
DOI：10.1186/1467-4866-5-33
出版社：BioMed Central
摘要：The reactivity of a mineral surface is determined by the variety and population of different types of surface sites (e.g., step, kink, adatom, and defect sites). The concept of "adsorbed nutrient" has been built into crystal growth theories, and many other studies of mineral surface reactivity appeal to ill-defined "active sites." Despite their theoretical importance, there has been little direct experimental or analytical investigation of the structure and properties of such species. Here, we use ex-situ and in-situ scanning tunneling microcopy (STM) combined with calculated images based on a resonant tunneling model to show that observed nonperiodic protrusions and depressions on the hematite (001) surface can be explained as Fe in an adsorbed or adatom state occupying sites different from those that result from simple termination of the bulk mineral. The number of such sites varies with sample preparation history, consistent with their removal from the surface in low pH solutions.
关键词：Hematite;Bias Voltage;Reorganization Energy;Solvent Reorganization;Periodic Surface Structure