Tunable Potassium Ion Conductivity and Magnetism in Substituted Layered Ferrates

Albrecht R, Hunger J, Hoelzel M, Suard E, Schnelle W, Doert T, Ruck M (2021)

Publication Type: Journal article

Publication year: 2021

Journal

European Journal of Inorganic Chemistry Wiley-VCH Verlag

Book Volume: 2021

Pages Range: 364-376

Journal Issue: 4

DOI: 10.1002/ejic.202000891

Abstract

Five substituted oxohydroxoferrates K2–x(Fe,M)4O7–y(OH)y (M=Si, Ge, Ti, Mn, Ir) were synthesized in a potassium hydroxide hydroflux with a molar base-water ratio q(K) of about 0.9. While the hexagonal prisms of K2–x(Fe,Ti)4O7–y(OH)y crystallize in P63/mcm, all other compounds form hexagonal plates with the trigonal space group P (Formula presented.) 1 m. The crystal structure of the oxohydroxoferrates resembles ß-alumina. It consists of honeycomb layers (Formula presented.) Fe2O6] of edge-sharing [FeO6] octahedra, where the hexagonal voids are capped by vertex-sharing [FeO4] tetrahedra pairs. The cavities between the oxoferrate layers host the potassium ions. Depending on M, the substitution affects different iron positions and varies between 5 and 20 %. The magnetic structures of the antiferromagnetic compounds were determined by neutron powder diffraction. The potassium ion conductivity was characterized by electrochemical impedance spectroscopy at room temperature. By storing the oxohydroxoferrates in air or annealing them at 700 °C the ion conductivity was significantly increased, e. g. to 5.0 ⋅ 10−3 S cm−1 for a pressed pellet of the iridium substituted compound.

Involved external institutions

Technische Universität Dresden DE Germany (DE) Technische Universität München (TUM) DE Germany (DE) Institute Laue-Langevin (ILL) FR France (FR) Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids DE Germany (DE)

How to cite

APA:

Albrecht, R., Hunger, J., Hoelzel, M., Suard, E., Schnelle, W., Doert, T., & Ruck, M. (2021). Tunable Potassium Ion Conductivity and Magnetism in Substituted Layered Ferrates. European Journal of Inorganic Chemistry, 2021(4), 364-376. https://doi.org/10.1002/ejic.202000891

MLA:

Albrecht, Ralf, et al. "Tunable Potassium Ion Conductivity and Magnetism in Substituted Layered Ferrates." European Journal of Inorganic Chemistry 2021.4 (2021): 364-376.

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