Title :
Experimental investigation of a local mixed state induced by a small ferroparticle in YBaCuO films
Author :
Nozdrin, Yu.N. ; Mel´nikov, A.S. ; Tokman, I.D. ; Vysheslavtsev, P.P. ; Aladyshkin, A.Yu. ; Kluenkov, E.B. ; Vorobiev, A.K.
Author_Institution :
Inst. for Phys. of Microstruct., Acad. of Sci., Nizhny Novgorod, Russia
fDate :
6/1/1999 12:00:00 AM
Abstract :
Direct local measurements of the characteristics of a mixed state induced by a magnetic field of a small ferromagnetic particle have been carried out in thin film YBaCuO samples, using a scanning Hall probe. The results provide evidence for an extremely low energy barrier for entry of vortex half-loops into high quality films and further breaking of these half-loops into vortex-antivortex pairs. The observed phenomena are consistent with the Josephson medium model. We obtained the temperature dependence of the intergrain critical current density, which points to strong pair breaking effects at the grain boundaries.
Keywords :
Cooper pairs; Hall effect; Josephson effect; barium compounds; critical current density (superconductivity); ferromagnetic materials; grain boundaries; high-temperature superconductors; magnetic particles; mixed state; superconducting thin films; yttrium compounds; Josephson medium model; YBaCuO; ferromagnetic particle; grain boundaries; high temperature superconductors; intergrain critical current density; local mixed state; scanning Hall probe; small ferroparticle; strong pair breaking effects; superconducting films; temperature dependence; vortex halfloops; vortex-antivortex pairs; Energy barrier; Hall effect devices; Magnetic field measurement; Magnetic fields; Magnetic films; Microstructure; Particle measurements; Physics; Superconducting films; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
