Search

Your search keyword '"Hunt, M.R.C."' showing total 22 results
Start Over Author "Hunt, M.R.C."
22 results on '"Hunt, M.R.C."'

6. Sulphur-containing compounds as a response in sea urchins exposed to alkylated silicon nanocrystals and SiO2-coated iron oxide nanoparticles

Author

Siller, L., Piticharoenphun, S., Lemloh, M.L., Horrocks, B.R., Kaulich, B., Gianoncelli, A., Hunt, M.R.C., Brummer, F., and Medakovic, D.

Subjects
Iron oxide nanoparticles, Toxicity, Silicon nanocrystals, Fourier transform infrared spectroscopy, Sea urchins
Abstract

We report the effects of exposure to alkylated silicon nanocrystals (‘alkyl-SiNCs’ at concentration ~ 7.2 mg/L) and -Fe2O3 nanoparticles coated with ultra-thin silica (‘SiO2-coated IONPs’ at concentration ~ 150 mg/L) on sea urchins Paracentrotus lividus and Arbacia lixula, respectively, studied with X-ray fluorescence (XRF) and Fourier transform infrared (FTIR) spectroscpoies using excitation from a synchrotron light source. A remarkably low mortality and low incidence of skeletal deformation is observed for exposure to both types of nanoparticles studied, despite the high concentrations employed in this work. XRF mapping demonstrates that both types of nanoparticle are found to agglomerate in the body of the sea urchins. FTIR spectra indicates that alkyl-SiNCs remain intact after ingestion and corresponding XRF maps show increased an oxygen throughout the organisms, possibly related to oxidation products arising from reactive oxygen species generated in the presence of the nanoparticles. Exposure to SiO2-coated IONPs is found to produce sulphur-containing species, which may be the result of a biological response in order to reduce the toxicity of the nanomaterial.

Published
2016

7. X-ray diffraction study of gold nitride films: observation of a solid solution phase

Author

Alves, L., Hase, T.P.A., Hunt, M.R.C., Brieva, A.C., and Siller, L.

Subjects
Gold -- Electric properties, Nitrides -- Electric properties, Nitrides -- Structure, Plasma etching -- Usage, X-ray spectroscopy -- Usage, X-rays -- Diffraction, X-rays -- Usage, Physics
Abstract

X-ray photoelectron spectroscopy and x-ray diffraction are used for examining the structure of nitride containing gold films produced by reactive ion sputtering and nitrogen plasma etching. The differences between the strain and lattice parameters of gold and gold nitride films are seen and explained by the interstitial nitrogen.

Published
2008

8. Reactions and luminescence in passivated Si nanocrystallites induced by vacuum ultraviolet and soft-x-ray photons

Author

Y.Chao, Krishnamurthy, S., Montalti, M., L.H. Lie, Houlton, A., Horrocks, B.R., Kjeldgaard, L., Dhanak, V.R., Hunt, M.R.C., and Siller, L.

Subjects
Photons -- Research, Scanning tunneling microscopy -- Analysis, Photoemission -- Research, Physics
Abstract

Alkylated silicon nanocrystallites was prepared by a combined electrochemical and thermal hydrosilylation process and these particles were investigated using scanning tunneling microscopy, synchrotron-radiation excited photoemission and x-ray excited optical luminescence (XEOL). The XEOL reveals that two emission bands are active upon soft-x-ray photon excitation and that photoluminescence intensity decreases with photon exposure, which is attributed to charge trapping within the film.

Published
2005

9. Nitrogen ion irradiation of Au(110): formation of gold nitride

Author

Šiller, L., Hunt, M.R.C., Brown, J.W., Coquel, J-M., Rudolf, P., Zernike Institute for Advanced Materials, and Surfaces and Thin Films

Abstract

Often metal nitrides posses unique properties for applications, such as great hardness, high melting points, chemical stability, novel electrical and magnetic properties. One route to the formation of metal nitride films is through ion irradiation of metal surfaces. In this report, the results of irradiation of Au(110) surfaces by nitrogen ions with kinetic energies of 0.5 and 2 keV are studied with high resolution X-ray photoemission spectroscopy. N1s core level spectra show clear evidence for the formation of a gold nitride at, or in close vicinity to, the surface–the first direct observation of nitride formation by this element. Subsurface molecular nitrogen is also observed, the relative concentration of which increases with irradiation energy. We suggest that the subsurface molecular nitrogen is most likely present in the form of trapped bubbles.

Published
2002

10. The Science Case for 4GLS

Author

Allan, R.J., Allen, M.P., Alexandrov, A.S., Ashfold, M.N.R., Atkinson, R., Avaldi, L., Bain, C.D., Bancroft, J., Barrett, S.D., Barron, L.D., Bayliss, S., Becker, U., Benning, L.G., Berrah, N., Binns, C., Bisby, R.H., Bizau, J.M., Blake, R.J., Bowler, M.A., Bowyer, J., Brettle, J., Briggs, D., Brown, L.M., Brown, W.A., Burke, P.G., Cacho, C., Carter, R., Catlow, R., Cernik, R.J., Chesters, M., Clark, S.A., Clarke, D.T., Clarke, J.A., Codling, K., Cogdell, R., Connaughton, D., Connerade, J.P., Costello, J.T., Crapper, M.D., Creaser, C., Currell, F.J., Davies, P.B., de Jong, M., Dessent, C., Dhanak, V.R., Dobson, D.M., Dobson, P.J., Doig, A.J., Donovan, R.J., Dumas, P., Dunn, K., Dutuit, O., Dyke, J.M., Eastham, D.A., Egdell, R.G., Eland, J.H.D., Emerson, D.R., Eriksson, M., Erman, P., Evans, A., Evans, H., Evans, S., Field, T., Fielding, H., Fisher, A., Flavell, W.R., Ford, R., Frasinski, L.J., Freeman, N., Galayda, J.N., Gardner, P., Garside, J., Gay, N.J., Gejo, T., George, M., Gray, M.D., Greenshaw, T.J., Greig, D., Halsall, M.P., Hamilton, B., Harrison, N.M., Hasnain, S.S., Hatherly, P.A., Heathcote, P., Helliwell, J.R., Henderson, C.M.B, Hepburn, J., Hill, J., Hirst, G., Hirst, J.D., Holland, D.M.P., Horn, A.B., Horton, P., Hunt, M.R.C., Hutchinson, H., Inglesfield, J.E., Ivanov, V.K., Johnson, C.A.F., Johnson, L.N., Jones, D., Jones, F.H., Jones, G.R., Jones, L., Kadodwala, M., Karlsson, L., Kennedy, E.T., King, G.C., King, M.R.F., Kirkman, I.W., Kleese, K., Knight, P.L., Kylstra, N., Larkins, F.P., Latimer, C., Lawley, K.P., Leggett, G.J., Lewis, R.A., Lindsey, K., Lu, J.R., Lyng, F.M., Macdonald, M.A., Malins, A., Marangos, J.P., Margaritondo, G., Marsi, M., Marston, G., Martin, S.R., Martin-Fernandez, M.L., Mason, N.J., Matthew, J.A.D., McCoustra, M.R.S., McGilp, J., McGovern, I.T., McGrath, R., Meldrum, R.A., Meyer, M., Millar, T.J., Mitchell, D., Møller, S.P., Molster, F.J., Moriarty, P., Morin, P., Munro, I.H., Murdin, B.N., Nahon, L., Newell, W.R., Noble, C.J., Nordgren, E.J., Norman, P.R., O'Brien, P., O'Neill, P., O'Shea, P., Owen, H., Pain, R., Papiz, M., Parker, A., Parker, J., Parr, A., Pattrick, R., Pemble, M.E., Picardo, M., Pidgeon, C.R., Pinheiro, T.J.T., Poliakoff, E.D., Poole, M.W., Potts, A., Potvliege, R., Powis, I., Price, S.D., Quinn, F.M., Radford, S., Rachlew-Källne, E., Raval, R., Read, F.H., Reddish, T.J., Ridley, P.A., Roberts, G., Russell, A.E., Ryan, A.J., Sapelkin, A., Sato, S., Schneider, A., Seddon, E.A., Shaw, E.A., Shen, T., Sherwood, P., Šiller, L., Smith, A.D., Smith, D.A., Smith, I., Smith, S.L., Snowdon, K., Softley, T.P., Sokell, E., Southworth, S.H., Srivistava, G.P., Stankiewicz, M., Sule-Suso, J., Sutherland, J.C., Surman, M., Svensson, S., Taylor, A.O., Temmerman, W.M., Thomas, A., Tiddy, G.J., Tobin, M., Towns-Andrews, Elizabeth, Towrie, M., Truscott, G., Tuckett, R.P., Turner, Tracy, Twigg, M.V., Vagdama, P., van der Hart, H.W., Volk, M., Vrakkring, M.J.J., Walker, I.C., Wander, A., Wasserman, S.P., Watanabe, M., Weightman, P., Welton, T., West, J.B., Wharton, C.W., Whitehead, J.C., Williams, G.P., Winick, H., Withnall, R., Woodruff, D.P., and Zayats, A.

Subjects
Q1
Published
2001

11. Proof for trivalent Sc ions in Sc-2 @ C-84 from high-energy spectroscopy

Author

Pichler, T., Hu, Z., Grazioli, C., Legner, S., Knupfer, M., Golden, M.S., Fink, J., Groot, F.M.F. de, Hunt, M.R.C., Rudolf, P., Follath, R., Jung, Ch., Kjeldgaard, L., Brühwiler, P., Inakuma, M., Shinohara, H., Inorganic Chemistry and Catalysis 1, Inorganic Chemistry and Catalysis, and Zernike Institute for Advanced Materials

Subjects
ELECTRONIC-STRUCTURE, X-RAY-ABSORPTION, SYMMETRY, Taverne, Physics::Atomic and Molecular Clusters, DIMETALLOFULLERENE SC-2-AT-C-84, TM-AT-C-82, FULLERENE CAGES, METALLOFULLERENE, SPECTRA, METALS, LA-AT-C-82
Abstract

The electronic structure and the valency of the Sc ions in the endohedral dimetallofullerene Sc-2 @ C-84 with D-2d symmetry are probed using high-energy spectroscopy. Comparison of the Sc 2p --> 3d x-ray-absorption spectrum with calculated ionic multiplet spectra shows that the Sc ions are trivalent. Detailed multiplet calculations including covalency indicate that the effective valency of the Sc(III) ions can be described by a formal charge transfer to the fullerene cage of 2.6 +/- 0.1. This illustrates that a purely ionic picture is not valid for the electronic structure of Sc-2 @ C-84, and that a more complex picture including finite hybridization between the Sc and the fullerene cage has to be applied.

Published
2000

12. Proof for trivalent Sc ions in Sc2@C84 from high-energy spectroscopy

Author

Pichler, T., Grazioli, C., Legner, S., Knupfer, M., Golden, M.S., Fink, J., Groot, F.M.F. de, Hunt, M.R.C., Rudolf, Petra, and Follath, R.

Subjects
Physics::Atomic and Molecular Clusters, Scheikunde
Abstract

The electronic structure and the valency of the Sc ions in the endohedral dimetallofullerene Sc 2 @C 84 with D 2d symmetry are probed using high-energy spectroscopy. Comparison of the Sc 2p ! 3d x-ray-absorption spectrum with calculated ionic multiplet spectra shows that the Sc ions are trivalent. Detailed multiplet calcu-lations including covalency indicate that the effective valency of the Sc~III! ions can be described by a formal charge transfer to the fullerene cage of 2.660.1. This illustrates that a purely ionic picture is not valid for the electronic structure of Sc 2 @C 84 , and that a more complex picture including finite hybridization between the Sc and the fullerene cage has to be applied.

Published
2000

17. Proof for trivalent Sc ions inSc2@C84from high-energy spectroscopy

Author

Pichler, T., primary, Hu, Z., additional, Grazioli, C., additional, Legner, S., additional, Knupfer, M., additional, Golden, M. S., additional, Fink, J., additional, de Groot, F.M.F., additional, Hunt, M.R.C., additional, Rudolf, P., additional, Follath, R., additional, Jung, Ch., additional, Kjeldgaard, L., additional, Brühwiler, P., additional, Inakuma, M., additional, and Shinohara, H., additional

Published
2000
Full Text
View/download PDF

21. THE STRUCTURAL AND VIBRATIONAL PROPERTIES OF C60 ADSORBED ON THE GRAPHITE(0001) SURFACE.

Author

HUNT, M.R.C. and PALMER, R.E.

Abstract

The exciting opportunities promised by the unique properties of C60 can only be fully exploited if the growth and properties of this material can be understood. To this end we have carried out a study of the structural and vibrational properties of C60 adsorbed on the graphite(0001) surface. We observed a novel high-order periodicity at monolayer coverages which indicates that even the weak corrugation potential of the surface can perturb the geometry of the overlayer. Vibrational spectra show a low-energy resonance in the inelastic scattering cross section which we correlate with a resonance feature observed in the electron attachment cross section of C60. The lack of a measurable perturbation in the resonance upon going from multilayer to monolayer coverage indicates that a weak physisorption bond exists between the molecules and the surface. [ABSTRACT FROM AUTHOR]

Published
1996
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results