Atomic Manipulation at Room Temperature
Lead Research Organisation:
University of Birmingham
Department Name: School of Physics and Astronomy
Abstract
Atomic manipulation with the scanning tunneling microscope (STM) is the extreme limit of nanotechnology. The experiments to date have generally been done at low temperatures, where the thermal energy is low enough that the atoms do not move around randomly. Atomic manipulation at room temperature is a new ball game. One approach is to anchor a molecule to the surface through a chemical bond, such that a particular target group is presented to the tip of the STM, which can be used as a molecular-scale source of electrons. The aim is to achieve bond-selective molecular manipulation - one of the frontiers of nanoscale science. Our understanding of the mechanisms of such manipulation (e.g., coupling between the electrons and the vibrations of the molecule, energy dissipation, symmetry rules, etc) is however in its infancy. The aim of this project is to investigate single molecule excitation and bond-selective dissociation with the STM, at room temperature, in carefully selected molecular systems, building on our previous work published in Nature last year. In the case of chlorobenzene and the related family of polychlorinated biphenyl (PCB) molecules, we will test a model we proposed for two-electron dissociation of the C-Cl bond, which involves symmetry-breaking, by vibrational excitation, which couples together otherwise disconnected ( orthogonal ) molecular orbitals. PCB's are environmentally harmful and we may in the process cast some light on how to break them down.In the case of small molecules chosen to present the S-S (disulphide) group, we will investigate the stability of the bond to charge injection, the competing ( non-adiabatic ) dynamical channels expected to arise as a result of resonance formation and the mechanism of S-S bond fission. This is relevant to the response of biological molecules, notably proteins, to ionising radiation (which generates low energy electrons), since different chains in a folded protein are often connected by S-S bonds between cysteine amino acids.Our recent experiments have established the Birmingham group amongst the leading atomic manipulation groups in the world. The purpose of the present grant proposal is to build on this foundation with a new generation of high impact, room temperature STM manipulation experiments designed to take the work on to the next level.
People |
ORCID iD |
| Richard Palmer (Principal Investigator) |
Publications
Alshammari K
(2020)
Optimization of sol-immobilized bimetallic Au-Pd/TiO2 catalysts: reduction of 4-nitrophenol to 4-aminophenol for wastewater remediation.
in Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
Ayodele O
(2019)
Synergistic Computational-Experimental Discovery of Highly Selective PtCu Nanocluster Catalysts for Acetylene Semihydrogenation
in ACS Catalysis
Bauer K
(2017)
A proximal retarding field analyzer for scanning probe energy loss spectroscopy.
in Nanotechnology
Cai R
(2020)
Gas-Phase Deposition of Gold Nanoclusters to Produce Heterogeneous Glycerol Oxidation Catalysts
in ACS Applied Nano Materials
Cai R
(2018)
Performance of Preformed Au/Cu Nanoclusters Deposited on MgO Powders in the Catalytic Reduction of 4-Nitrophenol in Solution.
in Small (Weinheim an der Bergstrasse, Germany)
Cai R
(2017)
A new method to prepare colloids of size-controlled clusters from a matrix assembly cluster source
in APL Materials
Cai R
(2020)
Scale-Up of Cluster Beam Deposition to the Gram Scale with the Matrix Assembly Cluster Source for Heterogeneous Catalysis (Catalytic Ozonation of Nitrophenol in Aqueous Solution)
in ACS Applied Materials & Interfaces
Chen Y
(2020)
Insight into the intrinsic mechanism of improving electrochemical performance via constructing the preferred crystal orientation in lithium cobalt dioxide
in Chemical Engineering Journal
| Description | We investigated chlorobenzene (CB) and the related family of polychlorinated biphenyl (PCB) molecules using scanning tunnelling microscopy (STM) at room temperature. PCBs are environmentally harmful and the aim was to understand controlled mechanisms for their dissociation, potentially elucidating possible processes of how to break them down. We found that for both PCB and CB there was a competition whereby the molecule either leaves the surface or a reaction at the surface is initiated. Using atomic manipulation in the STM at room temperature, we discovered that PCB molecules adsorbed onto silicon could be induced to adopt a more stable configuration, whereas in CB, intramolecular bonds could be broken liberating chlorine atoms onto the surface. |
| Exploitation Route | These molecular manipulation experiments allow us to examine chemical reactions at the atomic scale, helping to explain the precise mechanisms by which chemical bonds are made and broken at the molecular level. A significant finding from our work is the importance of the surface in the manipulation process, because, as well as providing the bonding environment for the molecules, it facilitates long-range interactions with molecules not directly under the STM tip. These findings contribute to the knowledge base of the atomic manipulation community as a whole, including groups such as the Polanyi (Nobel Laureate) group, working on surface directed chemical reactions in the STM. |
| Sectors | Chemicals,Environment |
| URL | http://pubs.acs.org/iapps/liveslides/pages/index.htm?mscNo=jz501819n |
| Description | Atomic manipulation in the STM offers the opportunity for true bottom-up device construction, manufacturing components at the atomic level, and is thus at the limit of miniaturisation. However, it is an incredibly slow process, and quite often requires cryogenic temperatures thus limiting its applicability outside of a laboratory. The work done under this grant investigated manipulation at room temperature, helping to bridge the gap between fundamental science and further applications of this research. In addition, an unexpected result of the work was the finding of a non-local process which allowed manipulation of many molecules not located directly under the STM tip. This opens up the possibility of serialisation of the atomic manipulation process, whereby the tip manipulates many molecules in one manipulation event. |
| Description | Scanwel Ltd |
| Organisation | Scanwel Ltd |
| Country | United Kingdom |
| Sector | Private |
| Start Year | 2006 |