Thumbnail
Access Restriction
Open

Author Gao, Jing ♦ Huang, Weifeng ♦ Qin, Shan ♦ Wu, Xiang
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY ♦ COMPRESSIBILITY ♦ ELECTRON-ELECTRON COLLISIONS ♦ ELECTRON-ELECTRON COUPLING ♦ ELECTRON-ELECTRON INTERACTIONS ♦ MANGANESE IONS ♦ PHASE TRANSFORMATIONS ♦ PHOSPHATES ♦ PRESSURE RANGE GIGA PA ♦ PRESSURE RANGE MEGA PA 10-100 ♦ SODIUM IONS ♦ SYNCHROTRON RADIATION ♦ TEMPERATURE RANGE 0273-0400 K ♦ X-RAY DIFFRACTION
Abstract Alluaudites are promising electrochemical materials benefited from the open structure. Structural variations of alluaudites Na{sub 2}M{sub 3}(PO{sub 4}){sub 3} (M{sub 3}=Fe{sub 3}, Fe{sub 2}Mn and FeMn{sub 2}) system have been studied by synchrotron radiation X-ray diffraction combined with diamond anvil cell technique up to ~10 GPa at room temperature. No phase transition is observed. The excellent structural stability is mainly due to the flexible framework plus strong covalent P-O bond. Mn{sup 2+} instead of Fe can be described as Na{sup +}+2Fe{sup 2+}→Mn{sup 2+}+Fe{sup 3+}+□ where □ represents a lattice vacancy. The replacement of Fe with larger Mn{sup 2+} is equivalent to applying negative chemical pressure to the material. And it causes a more compressible b-axis, lattice expansion, structural compressibility and intensifies the core/electron-electron interactions of Fe. External pressure effect produces anisotropic lattice shrinkage. Structural considerations related to these variations and promising application prospects are discussed. - Graphical abstract: Figure 1 The crystal structure of alluaudites Na{sub 2}M{sub 3}(PO{sub 4}){sub 3} (M{sub 3}=Fe{sub 3}, Fe{sub 2}Mn and FeMn{sub 2}) projected along the c-axis. Alluaudites adopt a flexible framework plus strong covalent P-O bond, which contribute to excellent structural stability up to ~10 GPa. Mn{sup 2+} instead of Fe can be described as Na{sup ++}2Fe{sup 2+}→Mn{sup 2+}+Fe{sup 3+}+□ where □ represents a lattice vacancy, and it is equivalent to applying negative chemical pressure to the host. The substitution causes a more compressible b-axis, lattice expansion, structural compressibility and intensifies the core/electron-electron interactions of Fe.
ISSN 00224596
Educational Use Research
Learning Resource Type Article
Publisher Date 2017-03-15
Publisher Place United States
Journal Journal of Solid State Chemistry
Volume Number 247


Open content in new tab

   Open content in new tab