A TIME OF FLIGHT NEUTRON POWDER RIETVELD REFINEMENT STUDY AT ELEVATED-TEMPERATURE ON A MONOCLINIC NEAR-STOICHIOMETRIC NASICON Academic Article uri icon

abstract

  • Time of flight neutron powder data were collected at elevated temperatures on a sample of NASICON of composition Na3.17Zr1.93Si1.9P1.1O12. This sample, prepared by reheating a commerically available NASICON to minimize the ZrO2 impurity, has been previously structurally refined from room temperature neutron diffraction data collected at Argonne National Laboratory. Conductivity measurements show a cusp at ca. 170C attributed to the monoclinic-rhombohedral transition and the purpose of this work was to explore the nature of the transition. Data runs were made at 143, 173, 202, 300, and 391C. No evidence for a crystal system change was found. The highest temperature data sets could not be refined satisfactorily by the Rietveld method using a rhombohedral model, but rather required a monoclinic cell in space group C2 c to achieve convergence. An explanation for the conductivity cusp is given in terms of a disordering of the sodium ions and a change in conduction pathways which lowers the barriers to ion movement. 1988.

published proceedings

  • JOURNAL OF SOLID STATE CHEMISTRY

author list (cited authors)

  • RUDOLF, P. R., CLEARFIELD, A., & JORGENSEN, J. D.

citation count

  • 22

complete list of authors

  • RUDOLF, PR||CLEARFIELD, A||JORGENSEN, JD

publication date

  • January 1988