Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-08T17:32:31.956Z Has data issue: false hasContentIssue false
  • English
  • Français

Structural studies of schultenite in the temperature range 125–324 K by pulsed single crystal neutron diffraction — hydrogen ordering and structural distortions

Published online by Cambridge University Press:  05 July 2018

C. C. Wilson
C. C. Wilson*
Affiliation:
ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX 11 OQX, UK
Get access Rights & Permissions [Opens in a new window]

Abstract

The structure of the mineral schultenite, PbHAsO4, has been studied using pulsed neutron single crystal diffraction. The low-temperature, low-symmetry structure is found to exhibit substantial ordering of the hydrogen atom onto one of two possible sites, which are equally occupied in the high-temperature phase above 313 K. The occupancies found at low temperature agree well with the normal behaviour for such a hydrogen ordering phase transition in this type of material. In addition the heavy atom lattice distortion has been characterised as a function of temperature and found to follow broadly the pattern of hydrogen ordering. Higher-temperature measurements at and above the phase transition confirm the high symmetry nature of the structure in this region, with no significant distortions from this within the resolution of the present data.

Keywords

hydrogen orderingpulsed single crystal neutron diffractionphase transitionschultenite
Type
Mineralogy
Information
Mineralogical Magazine , Volume 58 , Issue 393 , December 1994 , pp. 629 - 634
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1994

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Brown, P. J. and Matthewman, J. C. (1987) The Cambridge Crystallography Subroutine Library— Mark 3 Users’ Manual. Rutherford Appleton Laboratory Report, 4L-87-010, Didcot, Oxon, UK.Google Scholar
Dowty, E. (1992) ATOMS. A computer program for displaying atomic structures. Shape Software, Kingsport, Tennessee, USA.Google Scholar
Effenberger, H. and Pertlik, F. (1986) Schultenit, PbHAsO4, und PbHPO4: Synthesen und Kristall-strukturen nebst einer Diskussion zur Symmetrie. Tschermaks Min. Petr. Mitt., 35, 157–66.CrossRefGoogle Scholar
Lavrencic, B. B. and Petzelt, J. (1977) Raman study of the ferroelectric phase transition in PbHPO4 and PbHAsO4 . J. Chem. Phys., 67, 3890–6.Google Scholar
Lockwood, D. J., Ohno, N., Nelmes, R. J. and Arend, H. (1985) Dynamics and statics of the ferroelectric phase transition in PbHPO4. J. Phys. C. Sol. State Phys., 18, L559-L565.Google Scholar
Nelmes, R. J. (1980) The role of crystal structure determination in the study of structural phase transitions. Ferroelectrics, 24, 237–45.CrossRefGoogle Scholar
Wilson, C. C. (1990) The data analysis of reciprocal space volumes. In: Neutron Scattering Data Analysis 1990, (M. W. Johnson, ed.); pp. 145-63, IOP Conference Series 107, Adam Hilger, Bristol.Google Scholar
Wilson, C. C. (1994) Monitoring phase transitions using a single data frame in neutron time-of-fiight Laue diffraction. J. Appl. Cryst., in press.CrossRefGoogle Scholar
Wilson, C. C, Cox, P. J. and Stewart, N. S. (1991) Structure and disorder in schultenite, lead hydrogen arsenate. J. Cryst. Spectr. Res., 21, 589–93.CrossRefGoogle Scholar