title: Structural Evolution Induced by Interfacial Lattice Mismatch in Self-Organized YBa2Cu3O7-δNanocomposite Film.
abstract: Intriguing properties of self-organized nanocomposites of perovskite oxides are usually derived from the complex interface of constituent material phases. A sophisticated control of such a system is required for a broad range of energy and device applications, which demand a comprehensive understanding of the interface at the atomic scale. Here, we visualized and theoretically modeled the highly elastically strained nanorod, the interface region with misfit dislocations and heterointerface distortion, and the matrix with strain-induced oxygen vacancies in the self-organized YBa2Cu3O7-δnanocomposite films with Ba perovskite nanorods. Large misfit strain was elastically accommodated in the nanocomposites, but since the elastic strain was mainly accommodated by the nanorods, the concentration of strain-induced oxygen vacancies was small enough for the matrix to keep high critical temperature (>85 K). The interfacial bonding distorted the atomic structure of YBa2Cu3O7-δ, but the thickness of distortion was limited to a few unit cells (less than the coherence length) due to the electron screening. The effect of volume fraction on elastic strain and the electron screening are crucial for strong vortex pinning without significant degradation of both the elementary pinning force and critical temperature in the nanocomposites. Thus, we comprehensively clarified the self-organized nanocomposite structure for on-demand control of superconductivity and oxide functionality in the nanocomposite engineering of perovskite oxides.
authors.affiliation: Department of Materials Science and Engineering, Kyushu Institute of Technology , 1-1 Sensui-cho, Tobata-ku, Kitakyushu 804-8550, Japan.
authors.forename: Tomoya
authors.identifier: 0000-0003-1753-9179
authors.initials: T
authors.lastname: Horide
authors.affiliation: The Applied Superconductivity Center, National High Magnetic Field Laboratory, Florida State University , 2031 E. Paul Dirac Dr #240, Tallahassee, Florida 32310, United States.
authors.forename: Fumitake
authors.initials: F
authors.lastname: Kametani
authors.affiliation: Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University , 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Yoshioka
authors.affiliation: Department of Materials Science and Engineering, Kyushu Institute of Technology , 1-1 Sensui-cho, Tobata-ku, Kitakyushu 804-8550, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Kitamura
authors.affiliation: Department of Materials Science and Engineering, Kyushu Institute of Technology , 1-1 Sensui-cho, Tobata-ku, Kitakyushu 804-8550, Japan.
authors.forename: Kaname
authors.initials: K
authors.lastname: Matsumoto
keywords: Nanocomposite; interface; oxygen vacancy; strain; vortex pinning