Deliverables Process for purification and evaporation of C60 metallo-endohderal material Methods were developed for purifying endohedral metallo-C60 molecules using high performance liquid chromatography. Techniques were developed involving complex chemical washing procedures to produce the pure molecules. These results have been published in the open literature. The success of the purification process was characterised using spectroscopical methods such as IR, Raman and UV-vis and by laser desorption mass spectrometry. The Li@C60 material could be extracted and purified using these HPLC and chemical washing techniques and was distributed to the project partners. The extraction and purification was less successful for the higher alkalis although a small amount of purified material was produced. This can be partially attributed to the higher degree of material damage and polymerisation that occurs at the energies needed to produce the endohedral fullerenes and in the smaller probability of implantation to occur. The optimum conditions for evaporation of the purified molecules were tested and determined. The main aim was to provide material that could be evaporated under UHV conditions to form sub-monolayers or thicker films of purified endohedral fullerene molecules for electrical characterisation. The highly purified material was found to be extremely unstable under typical evaporation conditions. The deposited endohedral C60 molecules showed a strong and rapid degradation in electrical properties after deposition. The more stable La@C82 material showed a slower but still significant degradation in conductivity. More information on the Nice project can be found at: http://www.tyndall.ie/projects/nice/ Further development of UCAM nanostencil Continued development of the Cambridge nanostencil tool is being undertaken and extended to international collaborations, particularly for nanotechnology applications. The building of the nanostencil has been essentially completed and application of the tool to patterning of various materials is to be pursued. More information on the Nice project can be found at: http://www.tyndall.ie/projects/nice/ Fullerene MESFET device Controlled fabrication and in-situ electrical characterization of a three-terminal device with fullerene and metal materials has been achieved. The materials used in this first device are Cu and La@C82. Electrical characterization shows that the device does not work as a FET, i.e. the source-drain conductance cannot be controlled with the applied gate voltage. From current-voltage characteristics it is concluded that the device is space-charge limited. More information on the Nice project can be found at: http://www.tyndall.ie/projects/nice/ Low energy implantation source of implantation of fullerenes A new low energy ion source was designed, built and tested for cheap and efficient low energy ion implantation of fullerenes and related materials. The ion source is based on evaporation of the metal followed by surface ionisation on a heated rhenium grid. The characteristics of the source are currently being extensively tested. It can produce stable ion beams of a few hundred nA current for the alkali metals and Al at ion energies in the range 10-100eV. A new set of ion optics was designed, built and tested for extracting the ions from the source and introducing them to the implantation chamber. The production of endohedral fullerenes using this new, general source has been demonstrated. More information on the Nice project can be found at: http://www.tyndall.ie/projects/nice/ Endohedral metallo-C60 material A low energy ion implantation method was further developed for the production of endohedral metallo-fullerenes. Endohedral alkali-C60 and Al-C60 material was produced. The optimum implantation energy and dosage was determined for Li, K and Na implantation. The results of the optimisation were distributed to the project partners and published in the open literature. The method is unique in its ability to produce relatively large amounts of alkali containing C60. The Li@C60 material and some higher alkali materials were distributed to the project partners. For comparison, La@C82 was obtained from Japanese colleagues and its stability and optimised handling methods were determined. The results of these studies and the material were distributed to the project partners. The results were partially published in the open literature. More information on the Nice project can be found at: http://www.tyndall.ie/projects/nice/ Software procedure based upon OpenDX for STM image visualisation To compare the images obtained from scanning tunnelling microscopy with calculations of quantum mechanical density of states, graphical software must be interfaced to electronic structure codes. We have developed a set of DX instruction files which allows for the mapping of single electron orbitals onto constant current STM surfaces. The package takes as input the set of orbitals obtained from the quantum chemistry programme system TURBOMOLE and converts these to DX data objects. The constant current surface is then computed and the desired orbital is projected onto this surface and displayed. More information on the Nice project can be found at: http://www.tyndall.ie/projects/nice/ Materials paremeter set for fullerene simulation with device simulation tools (including Silvaco) Materials parameter sets for simulation of field effect transistors and transport properties of fullerenes have been determined for use with a commercial device simulator. Parameters needed are effective masses, band gaps, motilities, and relative band offsets for the fullerene materials. These parameters have been determined based upon the best known experimental values and optimisation and extraction relative to measurements on test structures. More information on the Nice project can be found at: http://www.tyndall.ie/projects/nice/ Nanostencil: Tool for nanopatterning unconventional materials The nanostencil tool has been further developed to allow unconventional materials to be deposited and structured on a sub-100 nm scale. The tool has been used to produce the various crossed-geometry structures of the NICE project, among them the first structures consisting of different materials (metal and fullerenes). In the future the nanostencil will be used as a flexible prototype nanopatterning tool, capable of producing very small structures of materials, which cannot be patterned by standard lithography methods. More information on the Nice project can be found at: http://www.tyndall.ie/projects/nice/ Investigating single molecular orbitals in fullerenes by novel STM Investigating single molecular orbitals in fullerenes by a novel scanning tunnelling microscopy mode of operation. Energy-resolved differential-conductance maps have been measured for individual C60 molecules adsorbed on a Cu(111) surface by means of low-temperature scanning tunnelling microscopy. To allow for the quantitative interpretation of these images as maps of local density of states a novel scanning mode has been applied, with the feedback loop switched off and the tip scanning in circles instead of scan lines. The energy-resolved maps obtained by this method can then be compared to density functional theory calculations. Thereby the nature of the fullerene-surface interaction is examined. More information on the Nice project can be found at: http://www.tyndall.ie/projects/nice/ Synchrotron characterisation of endohedral fullerenes To use endohedral fullerenes in technology applications, the interaction of the dopant atom with its environment must be explored. Synchrotron radiation studies provide a detailed means for determining electronic and geometrical information about doped fullerenes and their interactions with metal surfaces. These interactions have been detailed within the project, and future studies will consider other metal surfaces and dopant atoms. More information on the Nice project can be found at: http://www.tyndall.ie/projects/nice/ Searching for OpenAIRE data... There was an error trying to search data from OpenAIRE No results available
