Mechanism of Self-epitaxy in Buffer Layer for Coated Conductors

Takahiro Taneda, Masateru Yoshizumi, Takahiko Takahashi, Reiji Kuriki,
Takaomi Shinozaki, Teruo Izumi, Yuh Shiohara, Yasuhiro Iijima,
Takashi Saitoh, Ryuji Yoshida, Takeharu Kato,
Tsukasa Hirayama, and Takanobu Kiss

Abstract - To elucidate the self-epitaxy mechanism of pulsed-laser deposition (PLD)-CeO₂, a hypothetical relationship with the substrate was derived based on the ion-beam-assisted deposition (IBAD) layer-processing method: the smaller the misorientation angle, the larger the crystallite size. In-plane misorientation angle dependences of crystallite sizes of IBAD-MgO and LaMnO₃ as substrates for CeO₂ deposition, obtained using X-ray diffraction (XRD) and transmission electron microscopy (TEM), indicated that the hypothesis was plausible. This relationship is regarded as a prerequisite for self-epitaxy because large crystallites with small strains would be energetically favorable when CeO₂ particles crystallize on them. Eventually, they will grow to dominant grains, which is a possible self-epitaxy mechanism.

Keywords - CeO₂ buffer layer, IBAD, in-plane misorientation angle, Self-epitaxy, YBCO coated conductor

IEEE/CSC & ESAS European Superconductivity News Forum (ESNF) No. 22 October/November 2012.  ESNF Reference No.ST297 Category 2, 5.
The published version of this preprint appeared in IEEE Transactions on Applied Superconductivity 23, 6601005 (June 2013).