TY - JOUR
T1 - Chemical Pressure-Induced Anion Order-Disorder Transition in LnHO Enabled by Hydride Size Flexibility
AU - Yamashita, Hiroki
AU - Broux, Thibault
AU - Kobayashi, Yoji
AU - Takeiri, Fumitaka
AU - Ubukata, Hiroki
AU - Zhu, Tong
AU - Hayward, Michael A.
AU - Fujii, Kotaro
AU - Yashima, Masatomo
AU - Shitara, Kazuki
AU - Kuwabara, Akihide
AU - Murakami, Taito
AU - Kageyama, Hiroshi
N1 - Funding Information:
This work was supported by CREST (JPMJCR1421), JSPS KAKENHI (JP17H06439, JP17H06440, JP16H06441, and JP15H03849), PRESTO (JPMJPR1441), and JSPS postdoctoral fellowship (T.B.). Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award (EE13284). The neutron experiments were conducted at J-PARC (Proposal No. 2017A0064, 2017A0023, 2017L1300).
Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018/9/12
Y1 - 2018/9/12
N2 - While cation order-disorder transitions have been achieved in a wide range of materials and provide crucial effects in various physical and chemical properties, anion analogues are scarce. Here we have expanded the number of known lanthanide oxyhydrides, LnHO (Ln = La, Ce, Pr, Nd), to include Ln = Sm, Gd, Tb, Dy, Ho, and Er, which has allowed the observation of an anion order-disorder transition from the anion-ordered fluorite structure (P4/nmm) for larger Ln3+ ions (La-Nd) to a disordered arrangement (Fm3m) for smaller Ln3+ (Sm-Er). Structural analysis reveals that with the increase of Ln3+ radius (application of negative chemical pressure), the oxide anion in the disordered phase becomes too under-bonded, which drives a change to an anion-ordered structure, with smaller OLn4 and larger HLn4 tetrahedra, demonstrating that the size flexibility of hydride anions drives this transition. Such anion ordering control is crucial regarding applications that involve hydride diffusion such as catalysis and electrochemical solid devices.
AB - While cation order-disorder transitions have been achieved in a wide range of materials and provide crucial effects in various physical and chemical properties, anion analogues are scarce. Here we have expanded the number of known lanthanide oxyhydrides, LnHO (Ln = La, Ce, Pr, Nd), to include Ln = Sm, Gd, Tb, Dy, Ho, and Er, which has allowed the observation of an anion order-disorder transition from the anion-ordered fluorite structure (P4/nmm) for larger Ln3+ ions (La-Nd) to a disordered arrangement (Fm3m) for smaller Ln3+ (Sm-Er). Structural analysis reveals that with the increase of Ln3+ radius (application of negative chemical pressure), the oxide anion in the disordered phase becomes too under-bonded, which drives a change to an anion-ordered structure, with smaller OLn4 and larger HLn4 tetrahedra, demonstrating that the size flexibility of hydride anions drives this transition. Such anion ordering control is crucial regarding applications that involve hydride diffusion such as catalysis and electrochemical solid devices.
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U2 - 10.1021/jacs.8b06187
DO - 10.1021/jacs.8b06187
M3 - Article
C2 - 30126273
AN - SCOPUS:85052986299
VL - 140
SP - 11170
EP - 11173
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 36
ER -