TY - JOUR
T1 - Negative Knight Shift in Ba-Ti Oxyhydride
T2 - An Indication of the Multiple Hydrogen Occupation
AU - Misaki, Tai
AU - Oikawa, Itaru
AU - Takamura, Hitoshi
N1 - Funding Information:
This work was supported in part by JSPS KAKENHI Grant Number JP18H03832.
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/9/24
Y1 - 2019/9/24
N2 - Multiple hydrogen occupation in Ba-Ti oxyhydride is demonstrated by a negative Knight shift in the 1H magic-angle spinning (MAS) NMR spectra combined with hydrogen concentration and X-ray photoelectron spectroscopic analysis. A negative Knight shift, an indicator of the interaction between conduction band electrons and a probe nucleus, is observed in the 1H MAS NMR signal of Ba-Ti oxyhydrides at room temperature for the first time. This Knight shift indicates multiple hydrogen occupation. This was confirmed by the X-ray photoelectron spectra of Ba-Ti oxyhydrides and the hydrogen concentrations. The presence of hydrogen species with different bonding characteristics indicates a flexible hydrogen configuration in Ba-Ti oxyhydrides, from an ionic-state hydride ion with single occupation to partially anionic state hydrogen atoms with multiple occupation. It also indicates the potential to modify the electronic structure and physical properties of Ba-Ti oxyhydrides by manipulating their hydrogen configuration.
AB - Multiple hydrogen occupation in Ba-Ti oxyhydride is demonstrated by a negative Knight shift in the 1H magic-angle spinning (MAS) NMR spectra combined with hydrogen concentration and X-ray photoelectron spectroscopic analysis. A negative Knight shift, an indicator of the interaction between conduction band electrons and a probe nucleus, is observed in the 1H MAS NMR signal of Ba-Ti oxyhydrides at room temperature for the first time. This Knight shift indicates multiple hydrogen occupation. This was confirmed by the X-ray photoelectron spectra of Ba-Ti oxyhydrides and the hydrogen concentrations. The presence of hydrogen species with different bonding characteristics indicates a flexible hydrogen configuration in Ba-Ti oxyhydrides, from an ionic-state hydride ion with single occupation to partially anionic state hydrogen atoms with multiple occupation. It also indicates the potential to modify the electronic structure and physical properties of Ba-Ti oxyhydrides by manipulating their hydrogen configuration.
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U2 - 10.1021/acs.chemmater.9b01434
DO - 10.1021/acs.chemmater.9b01434
M3 - Article
AN - SCOPUS:85072900805
SN - 0897-4756
VL - 31
SP - 7178
EP - 7185
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 18
ER -