Summary
Transport properties of positroniumlike complexes formed in alkali halides are discussed. It is shown that the existing information is consistent with the diffusion approximation. Estimates drawn from angular-correlation data indicate that the diffusion constant of delocalized e+e- pairs in the low-temperature region is above 0.18 cm2 s-1 in NaI and KI, and above 0.30 cm2 s-1 in KCl, NaCl and NaF. The diffusion constant is expected to decrease above the transition that leads to the broadening of the angular-correlation curves. The nature of the system predominating above this transition is still to be ascertained. Here the transport mechanisms of two models are compared and the differences are made clear. It is shown that the experimental determination of the diffusion constant as a function of the temperature could give the key to the correct model assignment.
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References
T. Hyodo andY. Takakusa:J. Phys. Soc. Jpn.,42, 1065 (1977).
Y. Takakusa andT. Hyodo:J. Phys. Soc. Jpn.,45, 353 (1978).
T. Hyodo andY. Takakusa:J. Phys. Soc. Jpn.,45, 795 (1978).
Y. Takakusa andT. Hyodo:J. Phys. Soc. Jpn.,49, 2243 (1980).
J. Kasai andK. Fujiwara:J. Phys. Soc. Jpn.,51, 3077 (1982).
J. Kasai, T. Hyodo andK. Fujiwara:J. Phys. Soc. Jpn.,52, 3671 (1983).
K. Fujiwara:Positron Annihilation, inProceedings of the VI International Conference Positron Annihilation, 1982, edited byP. G. Coleman, S. C. Sharma andL. M. Diana (North-Holland, Amsterdam, 1983), p. 615.
A. Dupasquier: inPositrons in Solids, edited byP. Hautojärvi (Springer-Verlag, Berlin, Heidelberg, New York, N.Y., 1979), p. 197.
A. Dupasquier: inPositron Solid State Physics, edited byW. Brandt andA. Dupasquier (North-Holland, Amsterdam, Oxford, New York, N.Y., 1983), p. 510.
A. Bisi, A. Dupasquier andL. Zappa:J. Phys. C,4, L311 (1971).
A. Bisi, A. Dupasquier andL. Zappa:J. Phys. C,6, 1125 (1973).
D. Herlach:Helv. Phys. Acta.,45, 894 (1972).
A. Dupasquier:Lett. Nuovo Cimento,34, 246 (1982).
M. Eldrup, A. Vehanen, P. J. Schultz andK. G. Lynn:Phys. Rev. Lett.,51, 2007 (1983).
R. J. Douglas, M. Eldrup, L. Lupton andA. T. Stewart:Positron Annihilation, inProceedings of the V International Conference on Postiron Annihilation, 1979, edited byR. R. Hasiguti andK. Fujiwara (Japan Inst. Metals, Aoba Aramki, 1979), p. 621.
H. Ikari:Phys. Soc. Jpn.,46, 97 (1979).
O. V. Boev andK. P. Aref’ev:Fiz. Tverd. Tela (Leningrad),25, 1220 (1983) (English translation:Sov. Phys. Solid State,25, 701 (1983)).
A. P. Mills jr. : oral communication at the workshop onSlow Positrons in Surface Science, Pajulahti, Finland, June 25–29, 1984. Note added in proof: Mills’ actual measurement of the diffusion constant in NaFis (7 ± 2) · 10-3 cm2 s-1 (A. P. Mills: private communication, August 2, 1984).
T. Hyodo, J. Kasai andY. Takakusa:J. Phys. Soc. Jpn.,79, 2248 (1980).
J. Appel: inSolid State Physics, Vol.21, edited byF. Seitz, D. Turnbull andH. Ehrenreich (Academic Press, New York, N.Y., London, 1968), p. 193.
R. G. Fuller: inPoint Defects in Solids, edited byJ. H. Crawford Jr. andL. M. Slifkin (Plenum Press, New York, N.Y., London, 1972), p. 103.
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Work supported by the Italian Ministry of Education (MPI) and by the Gruppo Nazionale di Struttura della Materia of the Italian National Research Council (CNR).
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Dupasquier, A. Diffusion of positroniumlike systems in alkali halides. Lett. Nuovo Cimento 41, 443–447 (1984). https://doi.org/10.1007/BF02747152
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DOI: https://doi.org/10.1007/BF02747152