Iron Oxide Thin Film Growth On Ag(100)
(2014) FYSM31 20141Department of Physics
Synchrotron Radiation Research
- Abstract
- This thesis presents a study of iron oxide thin films, grown on a silver metal substrate, with the goal of characterizing the structures that form during growth of the first atomic layers. Such ultra-thin iron oxides are interesting model materials for fundamental surface chemistry and catalysis studies. The films were grown by reactive deposition of iron under ultra-high vacuum conditions and characterized by X-ray photoelectron spectroscopy (XPS), carried out at beamline I311 of the MAX IV laboratory, as well as scanning tunneling microscopy (STM), carried out in the Division of Synchrotron Radiation Research.
The aim of this project was to study the chemical composition and atomic scale structure of the oxide films. We find that... (More) - This thesis presents a study of iron oxide thin films, grown on a silver metal substrate, with the goal of characterizing the structures that form during growth of the first atomic layers. Such ultra-thin iron oxides are interesting model materials for fundamental surface chemistry and catalysis studies. The films were grown by reactive deposition of iron under ultra-high vacuum conditions and characterized by X-ray photoelectron spectroscopy (XPS), carried out at beamline I311 of the MAX IV laboratory, as well as scanning tunneling microscopy (STM), carried out in the Division of Synchrotron Radiation Research.
The aim of this project was to study the chemical composition and atomic scale structure of the oxide films. We find that there are different iron oxide phases on the Ag(100) surface that depending on the growth conditions. These can be described as 1) monolayer FeO(111) with FeO(100)-like grain boundaries, 2) a mixed FeO(111) and FeO(100) structure with FeO(100) grains party embedded in the surface, and 3) a hexagonal multilayer structure with a buckled top layer, observed under oxygen-rich conditions and attributed to Fe2O3. These results are important as they will form the basis for futher studies of FeO surface chemistry and catalysis using these films as well-defined model systems. (Less) - Popular Abstract
- Iron Oxide Films on Silver as a Model Catalyst
Catalysis is a key technology used in a broad range of applications in industry crucial for modern life. A catalyst is a material which selectively accelerates certain chemical reactions without being consumed, so that large-scale chemical processes can be carried out with lower costs and less waste. Catalysts are complex materials, however, and are difficult to characterize at the atomic level; thus to understand the catalysis on a fundamental, simplified model materials must be used. The goal of this thesis was to grow and characterize iron oxide films on a silver surface.
This experiments, which were carried out at the Dept. of Physics and the MAX IV Laboratory, we used scanning... (More) - Iron Oxide Films on Silver as a Model Catalyst
Catalysis is a key technology used in a broad range of applications in industry crucial for modern life. A catalyst is a material which selectively accelerates certain chemical reactions without being consumed, so that large-scale chemical processes can be carried out with lower costs and less waste. Catalysts are complex materials, however, and are difficult to characterize at the atomic level; thus to understand the catalysis on a fundamental, simplified model materials must be used. The goal of this thesis was to grow and characterize iron oxide films on a silver surface.
This experiments, which were carried out at the Dept. of Physics and the MAX IV Laboratory, we used scanning tunneling microscopy, low energy electron diffraction and x-ray photoelectron spectroscopy to characterize the chemical composition and atomic scale structures of iron oxide films grown on silver surface under various conditions. Indeed Scanning Tunneling Microscopy (STM) is a powerful technique for imaging surfaces thanks to its ability to resolve individual atoms and molecules and it is based on tunnelling the electron between two conductors; Low-energy electron diffraction (LEED) is an important technique to study the surface structure of crystalline materials and it is based on diffraction of electrons; X-ray Photoelectron Spectroscopy (XPS) is one of the most widely used techniques to investigate the chemical compositions of solid surfaces and it is based on photoelectric effect where a material is ionized by light. XPS measurements provide information about the elements present at the surface of a material as well as their chemical states. In this project three different iron oxide phases have been observed: 1) monolayer of Iron Oxide 2) a mixed different type of Iron Oxide surfaces, and 3) a hexagonal multilayer structure with a wavy structure. These results lay a foundation for further studies, which will investigate the differences in the chemical and catalytic properties of the three different phases. These films can be used as model materials for further studies, since iron oxides are interesting catalysts for a variety of oxidation reactions. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/4619114
- author
- Ataran, Sara LU
- supervisor
- organization
- course
- FYSM31 20141
- year
- 2014
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Surface Science, Material Science, XPS (X-Ray Photoelectron Spectroscopy), STM (Scaning Tunneling Microscopy), LEED (Low Energy Electron Diffraction)
- language
- English
- id
- 4619114
- date added to LUP
- 2014-09-18 09:58:00
- date last changed
- 2014-10-22 10:00:40
@misc{4619114,
abstract = {{This thesis presents a study of iron oxide thin films, grown on a silver metal substrate, with the goal of characterizing the structures that form during growth of the first atomic layers. Such ultra-thin iron oxides are interesting model materials for fundamental surface chemistry and catalysis studies. The films were grown by reactive deposition of iron under ultra-high vacuum conditions and characterized by X-ray photoelectron spectroscopy (XPS), carried out at beamline I311 of the MAX IV laboratory, as well as scanning tunneling microscopy (STM), carried out in the Division of Synchrotron Radiation Research.
The aim of this project was to study the chemical composition and atomic scale structure of the oxide films. We find that there are different iron oxide phases on the Ag(100) surface that depending on the growth conditions. These can be described as 1) monolayer FeO(111) with FeO(100)-like grain boundaries, 2) a mixed FeO(111) and FeO(100) structure with FeO(100) grains party embedded in the surface, and 3) a hexagonal multilayer structure with a buckled top layer, observed under oxygen-rich conditions and attributed to Fe2O3. These results are important as they will form the basis for futher studies of FeO surface chemistry and catalysis using these films as well-defined model systems.}},
author = {{Ataran, Sara}},
language = {{eng}},
note = {{Student Paper}},
title = {{Iron Oxide Thin Film Growth On Ag(100)}},
year = {{2014}},
}