Spin depolarization of muonium in mesoporous silica

Authors

M H. Dehn, Technical University of Munich
D J. Arseneau, TRIUMF
M D. Bridges, California State University, Fullerton
T Buck, University of British Columbia
David L. Cortie, University of British Columbia, TRIUMFFollow
S P. Cottrell, Rutherford Appleton Laboratory, UK
D G. Fleming, University of British Columbia, TRIUMF
J A. Kelly, University of British Columbia
W A. MacFarlane, University of British Columbia, TRIUMF
M J. MacLachlan, University of British Columbia
G D. Morris, TRIUMF
I McKenzie, TRIUMF
J Xiao, University of British Columbia
R F. Kiefl, TRIUMF, University of British Columbia

RIS ID

111590

Publication Details

Dehn, M. H., Arseneau, D. J., Bridges, M. D., Buck, T., Cortie, D. L., Cottrell, S. P., Fleming, D. G., Kelly, J. A., MacFarlane, W. A., MacLachlan, M. J., Morris, G. D., McKenzie, I., Xiao, J. & Kiefl, R. F. (2014). Spin depolarization of muonium in mesoporous silica. Journal of Physics: Conference Series, 551 012006-1-012006-6.

Abstract

We report muon spin rotation/relaxation measurements of muonium in mesoporous silica (SBA-15) with a high specific surface area of 600 m2/g. Up to 70 percent of the incoming muons form muonium and escape efficiently into the open pores at all temperatures between 3 and 300K. We present evidence that the interaction with the silica surfaces involves both spin exchange and a transition to a diamagnetic state, possibly due to dangling bonds on the surface. At very low temperatures, below 20K, the interaction between muonium and the silica surfaces is suppressed due to a He film coating the surfaces. These results indicate that it should be possible to use muonium to probe the surfaces of uncapped nanoparticles supported in silica.