TY - JOUR
T1 - Adatom Fe(III) on the hematite surface
T2 - Observation of a key reactive surface species
AU - Eggleston, Carrick M.
AU - Stack, Andrew G.
AU - Rosso, Kevin M.
AU - Bice, Angela M.
N1 - Publisher Copyright:
© American Institute of Physics 2004.
PY - 2004/6
Y1 - 2004/6
N2 - 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.
AB - 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.
KW - Bias Voltage
KW - Hematite
KW - Periodic Surface Structure
KW - Reorganization Energy
KW - Solvent Reorganization
UR - http://www.scopus.com/inward/record.url?scp=85199503970&partnerID=8YFLogxK
U2 - 10.1186/1467-4866-5-33
DO - 10.1186/1467-4866-5-33
M3 - Article
AN - SCOPUS:85199503970
SN - 1467-4866
VL - 5
JO - Geochemical Transactions
JF - Geochemical Transactions
IS - 2
M1 - 33
ER -