Title :
Size effects in electrical behavior of high-Tc thin-film bridges
Author :
Afanasyev, A.S. ; Gubankov, V.N. ; Divin, Yu.Ya.
Author_Institution :
Inst. of Radioeng. & Electron., Acad. of Sci., Moscow, USSR
fDate :
3/1/1991 12:00:00 AM
Abstract :
The size effects in electrical characteristics of polycrystalline YBa2Cu3O7-x thin-film bridges were studied in the temperature range 4-300 K. It is shown that at T>Tc the decrease of bridge widths w from 200 to 10 μm leads to an increase of resistance R□ of several times and to a change in R□ (T) behavior from a metallic type to an activation type. At T<Tc the R□ (w ) values exponentially increased from the width w was decreased under some definite size L0. At T<Tc the index α in the temperature dependence of critical current Ic(T )~(Tc-T)α changed from 3 to 1 if bridge width was decreased. Experimental data are discussed within the framework of the model which takes into account large-scale percolation processes in the system of different intergrain Josephson junctions, where characteristic length L0 of critical subnetwork is much larger than the grain size
Keywords :
Josephson effect; barium compounds; critical currents; high-temperature superconductors; size effect; superconducting junction devices; yttrium compounds; 4 to 300 K; YBa2Cu3O7-x; activation type; bridge widths; characteristic length; critical current; electrical behavior; high-temperature superconductors; intergrain Josephson junctions; large-scale percolation processes; model; size effects; thin-film bridges; Bridge circuits; Copper; Critical current; Electrical resistance measurement; Grain size; Josephson junctions; Magnetic films; Superconducting films; Temperature dependence; Transistors;
Journal_Title :
Magnetics, IEEE Transactions on
