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


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.


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.



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.


  1. Andrault D, Poirier JP (2002) Evolution of distortion of perovskites under pressure. An EXAFS study of BaZrO3, SrZrO3, and CaGeO3. Phys Chem Miner 18:91–105CrossRefGoogle Scholar
  2. Balić-Zunić T, Vicković I (1996) IVTON—a program for the calculation of geometrical aspects of crystal structures. J Appl Crystallogr 29:305–306CrossRefGoogle Scholar
  3. Carpenter MA, Howard CJ, Kennedy BJ, Knight KS (2005) Strain mechanism for order parameter coupling through successive phase transitions in PrAlO3. Phys Rev B 72:024118CrossRefGoogle Scholar
  4. Chakhmouradian AR, Ross K, Mitchell RH, Swainson I (2001) The crystal chemistry of synthetic potassium-bearing neighborite, (Na1−xKx)MgF3. Phys Chem Miner 28:277–284CrossRefGoogle Scholar
  5. Chen J, Liu H, Martin CD, Parise JB, Weidner DJ (2005) Crystal chemistry of NaMgF3 perovskite at high pressure and temperature. Am Miner 90:1534–1539CrossRefGoogle Scholar
  6. Cranswick LMD, Donaberger RL, Swainson IP (2005) C-2-“halfplus”: automating facility neutron diffraction equipment in preference to exhausting staff and users. In: American Crystallographic Association Annual Meeting 2005, Orlando, FL, USA (Abstract W0392)Google Scholar
  7. Goldschmidt HJ, Land T (1947) An X-ray investigation of the embrittlement of platinum and palladium-rhodium wires. J Iron Steel Inst 155:221–226Google Scholar
  8. Kern AA, Coelho AA (1998) TOPAS version 2.1: general profile and structure analysis software for powder diffraction data. Bruker AXS Karlsruhe, 79 ppGoogle Scholar
  9. Larsen AC, Von Dreele RB (1986) General structure analysis system (GSAS). Los Alamos National Laboaratory Report 86–748Google Scholar
  10. Mitchell RH (2002) Perovskites: modern and ancient. Almaz Press, Thunder Bay, 318 pp.
  11. Mitchell RH, Swainson IP (2004) Crystal structure of the fluoroperovskite KMgF3 at 20 K. Steacie Institute for Molecular Sciences, Neutron Program for Materials Research, Annual Report, 40–41Google Scholar
  12. Muradyan LA, Zavodnik VE, Makarova EP, Alexsandrov KS, Simonov VI (1984) Thermal vibrations of atoms in the structure of KMgF3 at 293 and 123 K. Kristallografiya 29:392–394Google Scholar
  13. Sasaki S, Prewitt CT, Liebermann RC (1983) The crystal structure of CaGeO3 perovskite and the crystal chemistry of GdFeO3 type perovskite. Am Miner 68:1189–1198Google Scholar
  14. Toby BH (2001) EXPGUI, a graphical user interface for GSAS. J Appl Crystallogr 34:210–213 CrossRefGoogle Scholar
  15. Touloukian YS, Kirby RK, Taylor RE, Desai PD (1975) Thermophysical properties of matter, vol 12. In: Thermal expansion: metallic elements and alloys. Plenum, New York, pp 254–259Google Scholar
  16. Wood IG, Knight KS, Price GD, Stuart JA (2002) Thermal expansion and atomic displacement parameters of cubic KMgF3 determined by high resolution neutron powder diffraction. J Appl Crystallogr 35:291–229CrossRefGoogle Scholar
  17. Wu GQ, Hoppe R (1984) Über die synthese von MLnF3 aus MLnF4. Z Anorg Allgem Chemie 514:92–98CrossRefGoogle Scholar
  18. Yoshiasa A, Sakamoto D, Okudera H, Ohkawa H, Ota K. (2003). Phase relations of Na1−xKxMgF3 (0 ≤ x ≤ 1) perovskite-type solid solutions. Mater Res Bull 38:421–427CrossRefGoogle Scholar
  19. Zhao Y (1998) Crystal chemistry and phase transitions of perovskites in P–T–X space: data for (Na1−xKx)MgF3 perovskites. J Solid State Chem 141:121–132CrossRefGoogle Scholar
  20. Zhao Y, Wiedner DJ (1991) Thermal expansion of SrZrO3 and BaZrO3 perovskites. Phys Chem Miner 18:294–301CrossRefGoogle Scholar
  21. Zhao Y, Weidner DJ, Parise JB, Cox DE (1993) Thermal expansion and structural distortion of perovskite—data for NaMgF3. Part I. Phys Earth Planet Inter 76:1–16CrossRefGoogle Scholar

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

Personalised recommendations