Title :
Probing Microscopic Strain Interplay Due to Impurity Doping and Vicinal Growth and Its Effect on Pinning Landscape in YBCO Films
Author :
Wu, Junyong ; Shi, Jack ; Baca, Javier ; Emergo, Rose ; Elliot, Alan ; Wilt, Jamie ; Sebastian, Mary Ann ; Haugan, Timothy ; Varanasi, Chakrapani V.
Author_Institution :
Dept. of Phys. & Astron., Univ. of Kansas, Lawrence, KS, USA
Abstract :
Vortex pinning by insertion of non-superconducting defects like BZO or BSO nanorods into the YBCO matrix is an effective means to enhance pinning since they self-assemble into columnar structures that provide strong pinning along the length of the flux-line. However, only limited control of their geometry is possible by current growth methods. To meet the requirements of applications that operate in magnetic fields of varying intensity or orientation, this work studies strain-mediated self-assembly of 3D pinning landscape through theoretical modeling as well as experimental exploration to achieve controllable growth BZO or BSO nanostructures in YBCO matrix films. The microstructure of BZO- and BSO-doped YBCO thin films was studied using transmission electron microscopy and the findings indicate that it is possible to produce a controllable defect landscape and improved critical current density with respect to different orientation of the magnetic field by manipulation of the strain relationships using vicinal substrates.
Keywords :
barium compounds; critical current density (superconductivity); crystal microstructure; doping; flux pinning; high-temperature superconductors; impurities; nanorods; self-assembly; superconducting thin films; transmission electron microscopy; yttrium compounds; 3D pinning landscape; YBCO-BaSnO3; YBCO-BaZrO3; critical current density; defect landscape; impurity doping; magnetic field orientation; microscopic strain; microstructure; nanorods; nanostructures; strain-mediated self-assembly; superconducting films; transmission electron microscopy; vicinal growth; vortex pinning; Lattices; Microstructure; Nanostructures; Self-assembly; Strain; Substrates; Yttrium barium copper oxide; Doping; doping; flux pinning; microstructure; strain; superconducting thin films;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2014.2369735