Abstract
During the period 1975–1990 there was an intense development, at some accelerator laboratories, of a new spectroscopy based on the interaction of an elementary particle, the positive muon, with local magnetic fields present in magnets and superconductors. It was called μSR (or in some applications MuSR), which stands for Muon Spin Rotation or Muon Spin Relaxation. At the present time this spectroscopy has given access to detailed information (often unobtainable with other means), on a large number of magnetic, semiconducting and superconducting systems, but the present article deals with another aspect of μSR, namely the information it could provide on how a light positive particle behaves when placed in a metallic environment. This behaviour has much in common with that of the technologically important “hydrogen in metal”-problem, but could now be studied in a very direct way since the positive muon is radioactive and sends out an easily detectable signal. This signal contains information on the particle’s local environment, its motion from one lattice position to another, its trapping and release from other impurity atoms in the metal and also on the character of the motion itself, particularly at low temperatures where quantum effects dominate. It took nearly 15 years to fully interpret and understand these phenomena which is the topic of the present historic presentation.
Similar content being viewed by others
References
B.E. Karlsson, Solid State Phenomena – as Seen by Muons, protons and Excited Nuclei (Oxford University Press, Oxford, 1993)
O. Hartmann, E. Karlsson, L.-O. Norlin, T.O. Niinikoski, K.W. Kehr, D. Richter, J.-M. Welter, A. Yaouanc, J. Le Hericy Studies of muon localization in Cu, Al, and Al-alloys in the temperature interval 0.03–100 K, Phys. Rev. Lett. 44, 337 (1980)
O. Hartmann, Quadrupole influence on the dipolar field width for a single interstitial in a metal crystal, Phys. Rev. Lett. 39, 832 (1977)
K.W. Kehr, D. Richter, J.-M. Welter, O. Hartmann, E. Karlsson, L.-O. Norlin, T.O. Niinikoski, A. Yaouanc, Muon diffusion in aluminium and dilute aluminium alloys. Experiments and comparison with small-polaron theory, Phys. Rev. B 26, 567 (1982)
O. Hartmann, E. Karlsson, E. Wäckelgård, R. Wäppling, D. Richter, R. Hempelmann, T.O. Niinikoski, Low temperature diffusion and trapping of muons in aluminium: new experiments and comparison with theory, Hyperfine Interactions 31, 223 (1986)
O. Hartmann, E. Karlsson, R. Wäppling, D. Richter, R. Hempelmann, K. Schulze, B. Patterson, E. Holzschuh, W. Kündig, S.F.J. Cox, Trap identification and impurity-induced localization of muons in Nb, Phys. Rev. B 27, 1943 (1983)
M. Borghini, T.O. Niinikoski, J.C. Soulié, O. Hartmann, E. Karlsson, L.-O. Norlin, K. Pernestål, K.W. Kehr, D. Richter, E. Walker, Muon diffusion in Nb in the presence of traps, Phys. Rev. Lett. 40, 1723 (1978)
O. Hartmann, L.-O. Norlin, A. Yaouanc, J. LeHericy, E. Karlsson, T.O. Niinikoski, Low temperature studies of muon localization in copper, Hyperfine Interactions 8, 533 (1981)
J.-M. Welter, D. Richter, R. Hempelmann, O. Hartmann, E. Karlsson, L.-O. Norlin, T.O. Niinikoski, D. Lenz, Muon diffusion in copper below 2 K, Z. Phys. B 52, 303 (1983)
J. Brewer, M. Celio, D.R. Harshman, R. Keitel, S.R. Kreitzman, G.M. Luke, Determination of the very slow μ+ hop rates in Cu by LLF-μSR, Hyperfine Interactions 31, 191 (1986)
J. Kondo, Muon diffusion in metals, Hyperfine Interactions 31, 117 (1986)
H. Wipf, K. Neumaier, H and D tunneling in niobium, Phys. Rev. Lett. 52, 1308 (1984)
J. Kondo, in Fermi Surface Effects, edited by J. Kondo and A. Yoshimori, Solid State Sciences 77 (Springer, Berlin, 1988)
Yu. Kagan, N.V. Prokofe’v, in Quantum Tunneling in Condensed Media, edited by Yu. Kagan and A.J. Legget (Elsevier, Amsterdam, 1992)
H.J. Fell, R. Hempelmann, O. Hartmann, S. Harris, R. Wäppling, Diffusion of positive muons in niobium doped with titanium. Ber, Bunsenges. Phys. Chem. 95, 1091 (1991)
R. Kadono, R.F. Kiefl, S.R. Kreizman, Q. Li, T. Pfiz, T.M. Riseman, H. Zhou, R. Wäppling, S.W. Harris O. Hartmann E. Karlsson R. Hempelman D. Richter T.O. Niinikoski L.P. Lee B. Sternlieb E.J. Ansaldo Quantum diffusion of the positive muon in the superconducting state of Al, Hyperfine Interactions 64, 737 (1993)
E. Karlsson, New aspects of tunneling of flight interstitial particles in solids, Physica B 202, 234 (1994)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Karlsson, E. The positive muon implanted in metals – a story full of surprises. EPJ H 39, 303–323 (2014). https://doi.org/10.1140/epjh/e2014-50018-2
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1140/epjh/e2014-50018-2