Fabrication of Hydrogen Boride Thin Film by Ion Exchange in MgB<sub>2</sub>
T. Hirabayashi,
S. Yasuhara,
S. Shoji,
A. Yamaguchi,
H. Abe,
S. Ueda,
H. Zhu,
T. Kondo,
M. Miyauchi
Affiliations
T. Hirabayashi
Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Tokyo 152-8552, Japan
S. Yasuhara
Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Tokyo 152-8552, Japan
S. Shoji
Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Tokyo 152-8552, Japan
A. Yamaguchi
Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Tokyo 152-8552, Japan
H. Abe
Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, Tsukuba 305-0044, Japan
S. Ueda
Synchrotron X-ray Station at SPring-8, National Institute for Materials Science, Hyogo 679-5148, Japan
H. Zhu
Department of Mechanical Engineering, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
T. Kondo
Department of Materials Science and Tsukuba Research Center for Energy Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8573, Japan
M. Miyauchi
Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Tokyo 152-8552, Japan
In this study, hydrogen boride films are fabricated by ion-exchange treatment on magnesium diboride (MgB2) films under ambient temperature and pressure. We prepared oriented MgB2 films on strontium titanate (SrTiO3) substrates using pulsed laser deposition (PLD). Subsequently, these films were treated with ion exchangers in acetonitrile solution. TOF-SIMS analysis evidenced that hydrogen species were introduced into the MgB2 films by using two types of ion exchangers: proton exchange resin and formic acid. According to the HAXPES analysis, negatively charged boron species were preserved in the films after the ion-exchange treatment. In addition, the FT-IR analysis suggested that B-H bonds were formed in the MgB2 films following the ion-exchange treatment. The ion-exchange treatment using formic acid was more efficient compared to the resin treatment; with respect to the amount of hydrogen species introduced into the MgB2 films. These ion-exchanged films exhibited photoinduced hydrogen release as observed in a powder sample. Based on the present study, we expect to be able to control the morphology and hydrogen content of hydrogen boride thin films by optimising the ion-exchange treatment process, which will be useful for further studies and device applications.
