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Metal‐insulator transition in nanocomposites of glass and RuO 2
Author(s) -
Kusy A.,
Stadler A.W.,
Mleczko K.,
Żak D.,
Pawłowski S.,
Szałański P.,
Zawiślak Z.,
Grabecki G.,
Plesiewicz W.,
Dietl T.
Publication year - 1999
Publication title -
annalen der physik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.009
H-Index - 68
eISSN - 1521-3889
pISSN - 0003-3804
DOI - 10.1002/(sici)1521-3889(199911)8:7/9<589::aid-andp589>3.0.co;2-w
Subject(s) - condensed matter physics , conductivity , weak localization , percolation (cognitive psychology) , percolation threshold , materials science , scaling , anderson localization , magnetic field , electron localization function , glass transition , metal , electron , electrical resistivity and conductivity , magnetoresistance , physics , polymer , quantum mechanics , composite material , geometry , mathematics , neuroscience , metallurgy , biology
We report on studies of interplay between percolation and quantum localization in mixtures consisting of glass grains and RuO 2 metal particles of average diameters 550 and 10 nm, respectively. A weak temperature dependence of conductivity σ ( T ) = a + bT α , where α ≅ 0.20, is found in the temperature region 0.04 < T < 1 K. Similarly, an anomalously small magnitude of magnetoconductivity is observed in the studied magnetic field range up to 5 T. These observations demonstrate that percolation nature of electron transport leads to a significant modification of quantum corrections to conductivity at the localization boundary. The conductivity at criticality obeys a dynamic scaling equation with the conductivity exponent μ = 1.65 as expected for one‐electron Anderson localization.