Affiliation:
1. Laboratory of Materials, Crystallochemistry and Applied Thermodynamics, Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis 1068, Tunisia
2. i3N & Department of Physics, University of Aveiro, 3810-193 Aveiro, Portugal
Abstract
Na1.5MnII3MnIII0.5(AsO4)3 and Na1.5MnII3FeIII0.5(AsO4)3 compounds were synthesized via a high-temperature solid-state combustion reaction. The obtained samples were submitted to structural, morphological, and electrical characterizations. X-ray diffraction measurements revealed that both compounds crystallize in the monoclinic system with the space group P21/c. The lattice parameters were determined to be a = 6.78344 Å, b = 12.93830 Å, c = 11.22825 Å, and β = 98.5374° for Na1.5MnII3MnIII0.5(AsO4)3, and a = 6.76723 Å, b = 12.9864 Å, c = 11.256 Å, and β = 98.8636° for Na1.5Mn2+3Fe3+0.5(AsO4)3. The structures consist of octahedral MnII and MnIII or FeIII ions connected by sharing edges, forming infinite chains. These chains are further connected by AsO4 tetrahedra, resulting in a three-dimensional anionic framework with tunnels parallel to the a-direction and cavities according to the c-direction. The structural models were validated using bond valence and charge distribution analyses. In addition to the structural characterization, the electric results depended on the crystal structures, indicating the potential of the studied materials for being used in several applications.
Funder
FEDER funds through the COMPETE 2020 Program and National Funds through FCT—Portuguese Foundation for Science and Technology
Associate Laboratory Institute of Nanostructures
Nanomodelling, and Nanofabrication—i3N., UCIBIO
Associate Laboratory i4HB
FCT—Portuguese Foundation for Science and Technology
Subject
Inorganic Chemistry,Condensed Matter Physics,General Materials Science,General Chemical Engineering