Flux pinning effects of Y2O3 nanoparticulate dispersions in multilayered YBCO thin films

✍ Scribed by T.A. Campbell; T.J. Haugan; I. Maartense; J. Murphy; L. Brunke; P.N. Barnes

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 511 KB
• Volume: 423
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2004.09.018

✦ Synopsis

The flux pinning effects of Y 2 O 3 nanoparticulate inclusions in YBa 2 Cu 3 O 7Àd (Y123 or YBCO) thin films using (Y 2 O 3 /Y123) • N multilayer structures were studied. The multilayer films were made with pulsed laser deposition (PLD) on SrTiO 3 and LaAlO 3 substrates with a Y 2 O 3 nanoparticulate Ôpseudo-layerÕ thickness ranging from 0.2 to 1.4 nm, and YBCO layer thickness varying from 7 to 50 nm. Scanning electron microscopy images showed well-defined nanoparticle formation on film surfaces, with an approximate number density of (0.8-1.6) • 10 11 particles/cm 2 depending on Y 2 O 3 thickness. Minor reductions in the critical temperature (T c ) were measured for each increase in Y 2 O 3 pseudo-layer thickness. Transport critical currents (77 K, self-field) of 3-5 MA/cm 2 were consistently achieved for composite films with 60.6 nm Y 2 O 3 pseudo-layer thicknesses. Magnetic J c measurements using vibrating sample magnetometry (H 6 9 T, @70 and 77 K) showed a degradation of film properties for Y 2 O 3 pseudo-layer thickness greater than 0.6 nm. A comparison to Y211/Y123 multilayer films showed the thinner Y 2 O 3 pseudo-layer films exhibited similar properties.