Nanorod Self-Assembly in High Jc YBa2Cu3O7−x Films with Ru-Based Double Perovskites

Materials

Terry G. Holesinger²  Matthew D. Feldmann²  Boris Maiorov²  Leonardo Civale²  John A. Kennison²  Yates J. Coulter²  Paul D. Dowden²  Javier F. Baca²  Paul H. Tobash¹  Eric D. Bauer¹ 

[1] Condensed Matter and Magnet Science, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA; E-Mails:;Superconductivity Technology Center, 30 Bikini Atoll Rd, Los Alamos, NM 87545, USA; E-Mails:

关键词: superconductivity;    film;    pulsed laser deposition;    self-assembly;    TEM;    STEM;   

DOI  :  10.3390/ma4112042

来源: mdpi

【 摘 要 】

Many second phase additions to YBa₂Cu₃O_7−x (YBCO) films, in particular those that self-assemble into aligned nanorod and nanoparticle structures, enhance performance in self and applied fields. Of particular interest for additions are Ba-containing perovskites that are compatible with YBCO. In this report, we discuss the addition of Ba₂YRuO₆ to bulk and thick-film YBCO. Sub-micron, randomly oriented particles of this phase were found to form around grain boundaries and within YBCO grains in bulk sintered pellets. Within the limits of EDS, no Ru substitution into the YBCO was observed. Thick YBCO films were grown by pulsed laser deposition from a target consisting of YBa₂Cu₃O_y with 5 and 2.5 mole percent additions of Ba₂YRuO₆ and Y₂O₃, respectively. Films with enhanced in-field performance contained aligned, self-assembled Ba₂YRuO₆ nanorods and strained Y₂O₃ nanoparticle layers. A 0.9 µm thick film was found to have a self-field critical current density (J_c) of 5.1 MA/cm² with minimum J_c(Θ, H=1T) of 0.75 MA/cm². Conversely, J_c characteristics were similar to YBCO films without additions when these secondary phases formed as large, disordered phases within the film. A 2.3 µm thick film with such a distribution of secondary phases was found to have reduced self-field J_c values of 3.4 MA/cm² at 75.5 K and J_c(min, Θ, 1T) of 0.4 MA/cm².

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.