The effect of doping on global lattice properties of magnetite Fe{sub 3-x}Me{sub x}O{sub 4} (Me=Zn, Ti and Al)

Journal Article · Wed Aug 15 04:00:00 EDT 2012 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2012.04.001· OSTI ID:22131110

Kakol, Z. ^[1]; Owoc, D. ^[2]; Przewoznik, J.; Sikora, M.; Kapusta, C. ^[1]; Zajac, D. ^[3]; Sabol, J. E. ^[4]; Honig, J. M. ^[5]

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1. AGH - University of Science and Technology, Faculty of Physics and Applied Computer Science, al. Mickiewicza 30, 30-059 Krakow (Poland)
2. University of Agriculture, Department of Forest Work Mechanization, al. Mickiewicza 21, 31-120 Krakow (Poland)
3. HASYLAB at DESY, Notkestrasse 85, Hamburg (Germany)
4. Chemical Consultant, Racine WI (United States)
5. Dept. of Chemistry, Purdue University, West Lafayette, IN (United States)

X-ray powder diffraction was measured in Fe{sub 3-x}Me{sub x}O{sub 4} (Me=Zn, Ti, Al; x<0.065), in T range 70-300 K to see the effect of different doping on global lattice properties. The experimental results have shown that some lattice properties (e.g., the cell volume) are dopand specific. This can be attributed to the difference in preferential sites occupation by dopants. As confirmed by EXAFS, Zn enters tetrahedral, while Ti octahedral lattice sites, differently affecting crucial octahedral iron positions in the spinel lattice. However, despite this fact, it was found that T dependence of both monoclinic angle and lattice parameters is universal for studied samples above and below the Verwey transition temperature T{sub V}. So, not the iron atoms in octahedral positions individually, but interactions between them are responsible for the Verwey transition character change with doping. - Graphical abstract: A low temperature magnetite cell volume vs. dopants content. Apparently, Zn, Ti and Al atoms have different effect on the global lattice properties at individual temperatures. However, the Verwey transition reacts to dopants in a similar manner, despite the different way the octahedral iron positions are affected. Highlights: Black-Right-Pointing-Pointer We measure powder diffraction and EXAFS on Fe{sub 3-x}Me{sub x}O{sub 4}, Me=Zn, Ti, Al (x<0.065), in T range 70-300 K. Black-Right-Pointing-Pointer XRD: atom-type independent changes of lattice parameters with T. Black-Right-Pointing-Pointer EXAFS: Zn replaces Fe on tetrahedral positions, Ti on octahedral positions. Black-Right-Pointing-Pointer Thus, some secondary interactions between ordering orbitals, not the primary one driving the Verwey transition, control the transition order.

• OSTI ID: 22131110
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Vol. 192; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ABSORPTION SPECTROSCOPY
DOPED MATERIALS
FINE STRUCTURE
INTERACTIONS
IRON
LATTICE PARAMETERS
MAGNETITE
MONOCLINIC LATTICES
SPINELS
TRANSITION TEMPERATURE
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY