title: Direct observation of site-selective hydrogenation and spin-polarization in hydrogenated hexagonal boron nitride on Ni(111).
abstract: We report the structural analysis and spin-dependent band structure of hydrogenated boron nitride adsorbed on Ni(111). The atomic displacement studied by using the normal incidence X-ray standing wave (NIXSW) technique supports the H-B(fcc):N(top) model, in which hydrogen atoms are site-selectively chemisorbed on boron atoms and N atoms remain on top of Ni atoms. The distance between the Ni plane and nitrogen plane did not change after hydrogenation, which implies that the interaction between Ni and N is 3d-π orbital mixing (donation and back-donation) even after hydrogenation of boron. The remaining π* peaks in near-edge X-ray absorption fine structure (NEXAFS) spectra are a manifestation of the rehybridization of sp2into sp3states, which is consistent with the N-B-N bonding angle derived from NIXSW measurement. The SPMDS measurement revealed the spin asymmetry appearing on hydrogenated h-BN, which was originated from a π related orbital with back donation from the Ni 3d state. Even though the atomic displacement is reproduced by the density functional theory (DFT) calculation with the H-B(fcc):N(top) model, the experimental spin-dependent band structure was not reproduced by DFT possibly due to the self-interaction error (SIE). These results reinforce the site-selective hydrogenation of boron and pave the way for efficient design of BN nanomaterials for hydrogen storage.
authors.affiliation: Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195, Japan.
authors.forename: Manabu
authors.identifier: http://orcid.org/0000-0001-8361-956X
authors.initials: M
authors.lastname: Ohtomo
authors.affiliation: National Institute for Materials Science, Tsukuba, Ibaraki 305-0047, Japan and National Institutes for Quantum and Radiological Science and Technology QST, Tokai, Naka, Ibaraki 319-1106, Japan. s_sakai@qst.go.jp.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yamauchi
authors.affiliation: University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Sun
authors.affiliation: Siberian Federal University, 79 Svobodniy av., Krasnoyarsk 660041, Russia.
authors.forename: Alex A
authors.initials: AA
authors.lastname: Kuzubov
authors.affiliation: Siberian Federal University, 79 Svobodniy av., Krasnoyarsk 660041, Russia.
authors.forename: Natalia S
authors.initials: NS
authors.lastname: Mikhaleva
authors.affiliation: Department of Chemistry, College of Natural Sciences, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Pavel V
authors.initials: PV
authors.lastname: Avramov
authors.affiliation: National Institutes for Quantum and Radiological Science and Technology QST, Tokai, Naka, Ibaraki 319-1106, Japan. s_sakai@qst.go.jp.
authors.forename: Shiro
authors.initials: S
authors.lastname: Entani
authors.affiliation: Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Matsumoto
authors.affiliation: National Institutes for Quantum and Radiological Science and Technology QST, Tokai, Naka, Ibaraki 319-1106, Japan. s_sakai@qst.go.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Naramoto
authors.affiliation: National Institute for Materials Science, Tsukuba, Ibaraki 305-0047, Japan and National Institutes for Quantum and Radiological Science and Technology QST, Tokai, Naka, Ibaraki 319-1106, Japan. s_sakai@qst.go.jp.
authors.forename: Seiji
authors.initials: S
authors.lastname: Sakai