Mössbauer Spectroscopic Characterization of Fe Occupation of Columns in the Nb<sub>28</sub>O<sub>70</sub> Structure
- 1 Departamento de Fisica, UFSC, Florianópolis, Brazil
Abstract
In search of an experimental route to produce linear arrays of spins without the use of nanotechnological tools, we have doped Nb 28 O 70 with sm all amounts of transition metal oxides (TM; in this case Fe 2 O 3 ) or rare-earth oxides 3 , and investigated the location of the alien metal (Fe in this case) in the structure. Previous AC magnetic susceptibility measurements at low temperatures have been consistent with the formation of arrays of TM magnetic moments along the widely spaced columns parallel to the crystallographic b -axis in the Nb 28 O 70 structure. To obtain further details about the TM distribution, the previous investigation has been extended now to include a room-temperature M ö ssbauer spectroscopic analysis of the Fe-doped material. The data are consistent with the presence of low-spin Fe 3+ ions in both octahedral and tetrahedral coordinations of oxygens, and confirm (as suggested in the previous work) that Fe also interchanges positions with Nb ions located at tetrahedrally coordinated sites in the columns of the structure.
- Dagotto, E., Hotta, T. and Moreo, A. (2001) Colossal Magnetoresistant Materials: The Key Role of Phase Separation. Physics Reports, 344, 1-153. https://doi.org/10.1016/S0370-1573(00)00121-6
- Burns, G. (1992) High-Temperature Superconductivity: An Introduction. Academic Press, Boston.
- Schilling, O.F. (2016) Green Function Calculations of Properties for the Magnetocaloric Layered Structures Based Upon FeMnAsP. SPIN, 6, 1650010. https://doi.org/10.1142/S2010324716500107
- Zhang, Y., Liu, L., Alvarez, G., Moreo, A. and Dagotto, E. (2021) Magnetic States of Quasi One-Dimensional Iron Chalcogenide Ba 2 FeS 3 . Physical Review B, 104, 125122. https://doi.org/10.1103/PhysRevB.104.125122
- Gao, S., Lin, L.-F., Laurell, P., Chen, Q., Huang, Q., et al. (2023) Spinon Continuum in the Heisenberg Quantum Chain Compound Sr 2 V 3 O 9 . arviv: 2307.12093.
- Schilling, O.F. and Ghivelder, L. (2000) Magnetic Properties of Iron-Doped Channels in H-Nb 2 O 5 . Journal of Physics: Condensed Matter, 12, 2825-2832. https://doi.org/10.1088/0953-8984/12/12/321
- Schilling, O.F. and Ghivelder, L. (2001) Magnetic Impurities in H-Nb 2 O 5 . Journal of Physics: Condensed Matter, 13, 11017-11026. https://doi.org/10.1088/0953-8984/13/48/326
- Bevan, D.J.M. and Hagenmuller, P. (1973) Non-Stoichiometric Compounds. Tungsten Bronzes, Vanadium Bronzes and Related Compounds. Pergamon Press, Oxford.
- Paduani, C., Samudio Pérez, C.A., Gobbi, D. and Ardisson, J.D. (2009) Mineralogical Characterization of Iron-Rich Clayey Soils from the Middle Plateau in the Southern Region of Brazil. Applied Clay Science, 42, 559-562. https://doi.org/10.1016/j.clay.2008.03.008
- Malden, P.J. and Meads, R.E. (1967) Substitution by Iron in Kaolinite. Nature, 215, 844-846. https://doi.org/10.1038/215844b0
- Petit, S. and Decarreau, A. (1990) Hydrothermal (200°C) Synthesis and Crystal Chemistry of Iron-Rich Kaolinites. Clay Minerals, 25, 181-196. https://doi.org/10.1180/claymin.1990.025.2.04