Benefit of high-pressure structure on sodium transport properties: Example with NaFeF3 post-perovskite

Open Ceramics

Agnieszka Wizner¹  Jean-Marc Grenèche²  Sandy Auguste³  Kevin Lemoine⁴  Yoshiyuki Inaguma⁴  Hiroshi Kojitani⁵  Masaki Akaogi⁵ 

[1] Corresponding author.;University of the Basque Country (UPV/EHU), Barrio Sarriena, s/n, 48940, Leioa, Spain;Center for Cooperative Research on Alternative Energies (CIC energiGUNE), Basque Research and Technology Alliance (BRTA), Alava Technology Park, Albert Einstein 48, 01510, Vitoria-Gasteiz, Spain;Department of Chemistry, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-8588, Japan;Institut des Molécules et des Matériaux du Mans, UMR CNRS 6283, Le Mans Université, Avenue Olivier Messiaen, 72085, Le Mans Cedex 9, France;

关键词: High-pressure synthesis;    Fluoride materials;    NIB materials;   

DOI  :  

来源: DOAJ

【 摘 要 】

In the search of promising Na-ion cathode materials, high-pressure synthesis method was applied to obtain sodium iron fluoride NaFeF3 with the post-perovskite lamellar structure. A two-step synthesis was performed: first, the Pnma orthorhombic perovskite structure NaFeF3 form (or Pv-NaFeF3, GdFeO3 type) was synthesized at 1270 ​K and 7.7 ​GPa, then the Cmcm orthorhombic post-perovskite structure (or pPv-NaFeF3, CaIrO3 type) was obtained using a second step at 700 ​K and 15 ​GPa. The post-perovskite form was stabilized under ambient conditions with a low amount of remaining perovskite phase (5 ​mol%). The Mössbauer analysis of pPv-NaFeF3 was firstly investigated with a paramagnetic structure obtained at 300 and 77 ​K, opposed to Pv-NaFeF3 magnetism reflecting the different [FeF6] polyhedra arrangements. Finally, the sodium migration within the framework of both structures was evaluated with the use of Bond Valence Energy Landscape (BVEL) calculations, resulting with an enhanced Na+ mobility within the pPv-NaFeF3 structure.

【 授权许可】

Unknown