TY - JOUR
T1 - Hydride-based antiperovskites with soft anionic sublattices as fast alkali ionic conductors
AU - Gao, Shenghan
AU - Broux, Thibault
AU - Fujii, Susumu
AU - Tassel, Cédric
AU - Yamamoto, Kentaro
AU - Xiao, Yao
AU - Oikawa, Itaru
AU - Takamura, Hitoshi
AU - Ubukata, Hiroki
AU - Watanabe, Yuki
AU - Fujii, Kotaro
AU - Yashima, Masatomo
AU - Kuwabara, Akihide
AU - Uchimoto, Yoshiharu
AU - Kageyama, Hiroshi
N1 - Funding Information:
This work was supported by Grants-in-Aid for Scientific Research on Innovative Areas “Mixed Anion” (No. JP16H06439; JP16H06440; JP16H06441; JP17H05491), JSPS Core-to-Core Program (A) Advanced Research Networks (16H00888), CREST (JPMJCR1421), and JSPS KAKENHI (18H03832). The neutron experiments were conducted at J-PARC (2019A0017, 2017L1302). The synchrotron radiation experiments were performed at the BL02B2 of SPring-8, with the approval of the Japan Synchrotron Radiation Research Institute (JASRI).
Publisher Copyright:
© 2021, The Author(s).
PY - 2021/12/1
Y1 - 2021/12/1
N2 - Most solid-state materials are composed of p-block anions, only in recent years the introduction of hydride anions (1s2) in oxides (e.g., SrVO2H, BaTi(O,H)3) has allowed the discovery of various interesting properties. Here we exploit the large polarizability of hydride anions (H–) together with chalcogenide (Ch2–) anions to construct a family of antiperovskites with soft anionic sublattices. The M3HCh antiperovskites (M = Li, Na) adopt the ideal cubic structure except orthorhombic Na3HS, despite the large variation in sizes of M and Ch. This unconventional robustness of cubic phase mainly originates from the large size-flexibility of the H– anion. Theoretical and experimental studies reveal low migration barriers for Li+/Na+ transport and high ionic conductivity, possibly promoted by a soft phonon mode associated with the rotational motion of HM6 octahedra in their cubic forms. Aliovalent substitution to create vacancies has further enhanced ionic conductivities of this series of antiperovskites, resulting in Na2.9H(Se0.9I0.1) achieving a high conductivity of ~1 × 10–4 S/cm (100 °C).
AB - Most solid-state materials are composed of p-block anions, only in recent years the introduction of hydride anions (1s2) in oxides (e.g., SrVO2H, BaTi(O,H)3) has allowed the discovery of various interesting properties. Here we exploit the large polarizability of hydride anions (H–) together with chalcogenide (Ch2–) anions to construct a family of antiperovskites with soft anionic sublattices. The M3HCh antiperovskites (M = Li, Na) adopt the ideal cubic structure except orthorhombic Na3HS, despite the large variation in sizes of M and Ch. This unconventional robustness of cubic phase mainly originates from the large size-flexibility of the H– anion. Theoretical and experimental studies reveal low migration barriers for Li+/Na+ transport and high ionic conductivity, possibly promoted by a soft phonon mode associated with the rotational motion of HM6 octahedra in their cubic forms. Aliovalent substitution to create vacancies has further enhanced ionic conductivities of this series of antiperovskites, resulting in Na2.9H(Se0.9I0.1) achieving a high conductivity of ~1 × 10–4 S/cm (100 °C).
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U2 - 10.1038/s41467-020-20370-2
DO - 10.1038/s41467-020-20370-2
M3 - Article
C2 - 33420012
AN - SCOPUS:85098934412
SN - 2041-1723
VL - 12
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 201
ER -