Title :
Critical current density in highly biaxially-oriented YBCO films: Can we control J/sub c/(77 K) and optimize up to more than 10/sup 6/ amp/cm/sup 2/?
Author :
Pan, V.M. ; Kasatkin, A.L. ; Svetchnikov, V.L. ; Komashko, V.A. ; Popov, A.G. ; Galkin, A.Yu. ; Freyhardt, H.C. ; Zandbergen, H.W.
Author_Institution :
Inst. of Metal Phys., Acad. of Sci., Kiev, Ukraine
fDate :
6/1/1999 12:00:00 AM
Abstract :
High-J/sub c/ YBCO conductors of the second generation are based on processing of YBCO highly-textured film, It is important to develop deposition techniques to control and optimize flux pinning in such films. The dominant contribution to net pinning force in YBCO films is from the growth-induced dislocations. The average density of such dislocations in low-angle tilt domain boundaries can exceed 10/sup 11//cm/sup 2/. For 2D fluxline lattice (FLL) correlated disorder induced by linear defects, a simplified approach is proposed to get some optimization criteria for the critical current density as a function of domain size, misorientation angle, etc. During YBCO films deposition onto highly-textured buffer layers growth dislocation structures can be varied, Comparison of the high-resolution transmission electron microscopy (HREM) data and J/sub c/(H) angular dependencies for CeO/sub 2/-buffered YBCO films exhibit how the dislocation distribution can affect the angular J/sub c/(H) behavior.
Keywords :
barium compounds; critical current density (superconductivity); dislocation density; flux pinning; flux-line lattice; high-temperature superconductors; superconducting thin films; transmission electron microscopy; yttrium compounds; 2D fluxline lattice correlated disorder; YBa/sub 2/Cu/sub 3/O/sub 7/; critical current density; domain size; growth-induced dislocations; high temperature superconductor; high-resolution transmission electron microscopy; highly biaxially-oriented YBCO films; low-angle tilt domain boundaries; misorientation angle; net pinning force; Buffer layers; Conducting materials; Conductive films; Critical current density; Educational programs; Magnetic cores; Magnetic films; Magnetic materials; Physics; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
