Publication Details

Dehn, M. H., Arseneau, D. J., Boni, P., Bridges, M. D., Buck, T., Cortie, D. L., Fleming, D. G., Kelly, J. A., MacFarlane, W. A., MacLachlan, M. J., McFadden, R. M. L., Morris, G. D., Wang, P., Xiao, J., Zamarion, V. M. & Kiefl, R. F. (2016). Communication: Chemisorption of muonium on gold nanoparticles: A sensitive new probe of surface magnetism and reactivity. Journal of Chemical Physics, 145 (18), 181102-1-181102-5.


Chemisorption of muonium onto the surface of gold nanoparticles has been observed. Muonium (u+e-), a light hydrogen-like atom, reacts chemically with uncapped 7 nm gold nanoparticles embedded in mesoporous silica (SBA-15) with a strong temperature-dependent rate. The addition rate is fast enough to allow coherent spin transfer into a diamagnetic muon state on the nanoparticle surface. The muon is well established as a sensitive probe of static or slowly fluctuating magnetic fields in bulk matter. These results represent the first muon spin rotation signal on a nanoparticle surface or any metallic surface. Only weak magnetic effects are seen on the surface of these Au nanoparticles consistent with Pauli paramagnetism.



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