Na1.82K0.38Rb0.80Fe3(AsO4)4: Synthesis, crystal structure and alkali conduction pathways simulation

Eya Rezgui, Laboratory of Materials, Crystallochemistry and Applied Thermodynamics, Faculty of Sciences of Tunis, University of Tunis El Manar, Tunisia
2020 International Journal of Electrochemical Science  
A new iron arsenate Na1.82K0.38Rb0.80Fe3(AsO4)4 (1), with layer structure has been synthesized by solidstate method and studied by X-ray diffraction. It crystallizes in orthorhombic space group Cmce with lattice parameters a=10.8710(9)Å, b=20.882(2)Å, c=6.5163(7)Å, V= 1479.3(2)Å 3 and Z = 4. The final agreement factors are R = 0.039 and wR = 0.109. The X-ray single-crystal structure reveals a layered structure. Each layer is made of AsO4 tetrahedra and FeO6 octahedra sharing corners and edges.
more » ... he Rb + and K + reside between the undulating iron arsenate slabs, whereas the smaller Na + cations are located in the cavities of the anionic framework. The structural model was validated by bond valence sum (BVS), distortion indices (DI) and charge distribution (CD) methods. Pathways migration simulation of alkali cations was studied by extended BVS models (BVSP and BVEL).
doi:10.20964/2020.06.85 fatcat:bmmpxzpmmvalxardjxg53yuqcq