Title :
Laser probing of high-Tc superconducting thin films
Author :
Divin, Yu.Ya. ; Nad, F. Ya ; Pokrovski, V.Ya. ; Shadrin, P.M.
Author_Institution :
Inst. of Radioeng. & Electron., Acad. of Sci., Moscow, USSR
fDate :
3/1/1991 12:00:00 AM
Abstract :
The spatial inhomogeneity of the electrical characteristics of high-Tc thin films was studied by optical laser probing. It was shown that the characteristic length L of inhomogeneous current distribution in high-Tc films may be much larger than the grain size a; for example, in polycrystalline YBa2Cu3 O7-x film with critical current densities jc(4.2 K) ~103-104 A/cm2 and grain size a ~1 μm, the characteristic length L was equal to ~15 μm at T>Tc and ~100 μm at T≲Tc. The large values of L are related to large-scale percolation in the system of intergrain Josephson junctions with very wide distribution of critical currents Ici and normal-state resistances Rni
Keywords :
Josephson effect; barium compounds; critical current density (superconductivity); current distribution; grain size; high-temperature superconductors; laser beam applications; superconducting thin films; yttrium compounds; YBa2Cu3O7-x; characteristic length; critical current densities; critical currents; electrical characteristics; grain size; high temperature superconductivity; high-Tc superconducting thin films; inhomogeneity; inhomogeneous current distribution; intergrain Josephson junctions; large-scale percolation; normal-state resistances; optical laser probing; polycrystal; Electric variables; Electron beams; Grain size; Josephson junctions; Laser theory; Optical films; Semiconductor thin films; Superconducting films; Superconducting materials; Superconducting thin films;
Journal_Title :
Magnetics, IEEE Transactions on
