skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Mn, Mg, and Zn ilmenite group titanates: A reconnaissance rietveld study

Abstract

Ecandrewsite-geikielite (Zn{sub 1/2}Mg{sub 1/2}TiO{sub 3}), ecandrewsite-pyrophanite (Zn{sub 1/2}Mn{sub 1/2}TiO{sub 3}), pyrophanite-geikielite (Mg{sub 1/2}Mn{sub 1/2}TiO{sub 3}), and ecandrewsite-pyrophanite-geikielite (Zn{sub 1/3}Mn{sub 1/3}Mg{sub 1/3}TiO{sub 3}) titanates were synthesized at 900-1000 deg. C at ambient pressure. All of the compounds adopt R- ilmenite-type structures. These structures were refined by the Rietveld method from X-ray powder diffraction data. Unit cell parameters and unit cell volumes decrease with decreasing average radii of the A{sup 2+} cation. All structures consist of distorted AO{sub 6} and TiO{sub 6} octahedra. In common with pyrophanite and ilmenite, the distortion of the AO{sub 6} octahedra is less than that of the TiO{sub 6} octahedra. Data are given for the volumes and distortion indexes of all coordination polyhedra.

Authors:
 [1];  [2]
+ Show Author Affiliations
  1. Russian Academy of Sciences, Geological Institute, Kola Science Center (Russian Federation)
  2. Lakehead University, Department of Geology (Canada), E-mail: rmitchel@lakeheadu.ca
Publication Date:
OSTI Identifier:
21091487
Resource Type:
Journal Article
Resource Relation:
Journal Name: Crystallography Reports; Journal Volume: 51; Journal Issue: 3; Other Information: DOI: 10.1134/S1063774506030047; Copyright (c) 2006 Nauka/Interperiodica; Article Copyright (c) 2006 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ILMENITE; MAGNESIUM COMPOUNDS; MANGANESE COMPOUNDS; TITANATES; X-RAY DIFFRACTION; ZINC COMPOUNDS

Citation Formats

Liferovich, R. P., and Mitchell, R. H.. Mn, Mg, and Zn ilmenite group titanates: A reconnaissance rietveld study. United States: N. p., 2006. Web. doi:10.1134/S1063774506030047.
Copy to clipboard
Liferovich, R. P., & Mitchell, R. H.. Mn, Mg, and Zn ilmenite group titanates: A reconnaissance rietveld study. United States. doi:10.1134/S1063774506030047.
Copy to clipboard
Liferovich, R. P., and Mitchell, R. H.. Mon . "Mn, Mg, and Zn ilmenite group titanates: A reconnaissance rietveld study". United States. doi:10.1134/S1063774506030047.
Copy to clipboard
@article{osti_21091487,
title = {Mn, Mg, and Zn ilmenite group titanates: A reconnaissance rietveld study},
author = {Liferovich, R. P. and Mitchell, R. H.},
abstractNote = {Ecandrewsite-geikielite (Zn{sub 1/2}Mg{sub 1/2}TiO{sub 3}), ecandrewsite-pyrophanite (Zn{sub 1/2}Mn{sub 1/2}TiO{sub 3}), pyrophanite-geikielite (Mg{sub 1/2}Mn{sub 1/2}TiO{sub 3}), and ecandrewsite-pyrophanite-geikielite (Zn{sub 1/3}Mn{sub 1/3}Mg{sub 1/3}TiO{sub 3}) titanates were synthesized at 900-1000 deg. C at ambient pressure. All of the compounds adopt R- ilmenite-type structures. These structures were refined by the Rietveld method from X-ray powder diffraction data. Unit cell parameters and unit cell volumes decrease with decreasing average radii of the A{sup 2+} cation. All structures consist of distorted AO{sub 6} and TiO{sub 6} octahedra. In common with pyrophanite and ilmenite, the distortion of the AO{sub 6} octahedra is less than that of the TiO{sub 6} octahedra. Data are given for the volumes and distortion indexes of all coordination polyhedra.},
doi = {10.1134/S1063774506030047},
journal = {Crystallography Reports},
number = 3,
volume = 51,
place = {United States},
year = {Mon May 15 00:00:00 EDT 2006},
month = {Mon May 15 00:00:00 EDT 2006}
}
Copy to clipboard
Journal Article:
DOI:  10.1134/S1063774506030047
Other availability
Find in Google Scholar Find in Google Scholar
Search WorldCat Search WorldCat to find libraries that may hold this journal
Save / Share:
Export Metadata
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.

  • ; ; ; ... - Physical Review B
    Cited by 6

  • ; ; ; ... - Physical Review B
    Here we have performed inelastic neutron scattering (INS) experiments to investigate the magnetic excitations in the weakly distorted face-centered-cubic (fcc) iridate double perovskites Lamore » $$_2$$ZnIrO$$_6$$ and La$$_2$$MgIrO$$_6$$, which are characterized by A-type antiferromagnetic ground states. The powder inelastic neutron scattering data on these geometrically frustrated $$j_{\rm eff}=1/2$$ Mott insulators provide clear evidence for gapped spin wave excitations with very weak dispersion. The INS results and thermodynamic data on these materials can be reproduced by conventional Heisenberg-Ising models with significant uniaxial Ising anisotropy and sizeable second-neighbor ferromagnetic interactions. Such a uniaxial Ising exchange interaction is symmetry-forbidden on the ideal fcc lattice, so that it can only arise from the weak crystal distortions away from the ideal fcc limit. This may suggest that even weak distortions in $$j_{\rm eff}=1/2$$ Mott insulators might lead to strong exchange anisotropies. More tantalizingly, however, we find an alternative viable explanation of the INS results in terms of spin models with a dominant Kitaev interaction. In contrast to the uniaxial Ising exchange, the highly-directional Kitaev interaction is a type of exchange anisotropy which is symmetry-allowed even on the ideal fcc lattice. The Kitaev model has a magnon gap induced by quantum order-by-disorder, while weak anisotropies of the Kitaev couplings generated by the symmetry-lowering due to lattice distortions can pin the order and enhance the magnon gap. In conclusion, our findings highlight how even conventional magnetic orders in heavy transition metal oxides may be driven by highly-directional exchange interactions rooted in strong spin-orbit coupling.« less
    Cited by 6

  • ; ; ; ... - Physical Review B
    Cited by 4

  • ; - Geology; (USA)
    Whole-rock sulfur isotopic ratios were determined for four magnetite-series and two ilmenite-series granitoids from the central Sierra Nevada batholith. The magnetite-series rocks yielded {delta}{sup 34}S{sub (CDT)} of 1.6 to 4.0, and the ilmenite-series rocks revealed lower values of {minus}3.7 and {minus}5.3. These correlations are the same as those observed in the Japanese Islands arc. A majority of the Sierra Nevada granitoids are considered to have positive {sup 34}S values as a result of island-arc magmatism. The same magma was reduced by the introduction of organic carbon from the sedimentary wall rocks along the western zone where the depth of granitoidmore » emplacement was as deep as 4-5 kbar, thus forming the ilmenite-series granitoids.« less

  • ; ; ; ... - Materials Research Bulletin
    Two series of mixed oxides with formula [Eu{sub 2-x}M{sub x}][Sn{sub 2-x}M{sub x}]O{sub 7-3x/2} (M = Mg or Zn) have been synthesized. The study by X-ray diffraction and Fourier transform infrared spectroscopy shows that the solids obtained are new non-stoichiometric solid solutions with the pyrochlore type structure. For both series a decrease of the cell parameter is observed when the degree of substitution, x, increases. The structural refinements (X-ray studies) were achieved in the space group Fd-3m, no. 227 (origin at center -3m) by using the Fullprof software. The Rietveld refinements show that the divalent cations M{sup 2+} (Mg{sup 2+}, Zn{supmore » 2+}) substitute isomorphically for Eu{sup 3+} and Sn{sup 4+} ions producing vacancies in the anionic sublattice.« less