Abstract

The structure of tetragonal NbOPO4has been studied from room temperature to 500°C by X-ray powder diffraction and to 327°C by neutron powder diffraction. Rietveld refinements were conducted on neutron data collected at 25, 100, 175, 200, 225, 275, and 327°C. A phase transition was found at about 200°C. The space group isP4/nbelow this transition andP4/nmmabove this transition. Theccell edge shows positive thermal expansion over the entire temperature range. Theaandbcell edges show positive thermal expansion below the transition and negative thermal expansion above the transition. The negative thermal expansion is attributed to rocking motions of the corner-shared NbO6octahedra and PO4tetrahedra.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.