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Physics and Chemistry of Minerals

, Volume 33, Issue 8–9, pp 587–591 | Cite as

Neutron diffraction determination of the cell dimensions and thermal expansion of the fluoroperovskite KMgF3 from 293 to 3.6 K

  • Roger H. Mitchell
  • Lachlan M. D. Cranswick
  • Ian Swainson
Original Paper

Abstract

The cell dimensions of the fluoroperovskite KMgF3 synthesized by solid state methods have been determined by powder neutron diffraction and Rietveld refinement over the temperature range 293–3.6 K using Pt metal as an internal standard for calibration of the neutron wavelength. These data demonstrate conclusively that cubic \( Pm\overline{3} m \) KMgF3 does not undergo any phase transitions to structures of lower symmetry with decreasing temperature. Cell dimensions range from 3.9924(2) Å at 293 K to 3.9800(2) Å at 3.6 K, and are essentially constant within experimental error from 50 to 3.6 K. The thermal expansion data are described using a fourth order polynomial function.

Keywords

Cell Dimension Neutron Beam Rietveld Refinement Neutron Diffraction Pattern Solid Solution Series 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgments

This work is supported by the Natural Sciences and Engineering Research Council of Canada and Lakehead University. Kevin Knight is thanked for providing a table of the cell dimensions of KMgF3 as determined by Wood et al. (2002), and for comments on the initial draft of the manuscript. Miguel Watson is thanked for annealing the Pt foil used as the reference, and Larry McEwen for machining the V cans.

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Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Roger H. Mitchell
    • 1
  • Lachlan M. D. Cranswick
    • 2
  • Ian Swainson
    • 2
  1. 1.Department of GeologyLakehead UniversityThunder BayCanada
  2. 2.Chalk River LaboratoriesNational Research Council of Canada, Neutron Program for Materials Research, Steacie Institute for Molecular SciencesChalk River Canada

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