Structural Distortions and Phase Transformations in Sm2Zr2O7 Pyrochlore at High Pressures

Journal Article · Mon Jan 01 04:00:00 EST 2007 · Chemical Physics Letters

DOI:https://doi.org/10.1016/j.cplett.2007.05.018· OSTI ID:930467

Zhang, F; Lian, J; Becker, U; Wang, L; Hu, J; Saxena, S; Ewing, R

The structural characteristics of Sm{sub 2}Zr{sub 2}O{sub 7}, an ordered pyrochlore, were studied by angle-dispersive X-ray diffraction (XRD) and Raman scattering methods with increasing pressure. A structural distortion was observed at low pressures; but the distortion disappeared at pressures above 13.5 GPa. Above 18 GPa, the pyrochlore structure is unstable and a pressure-induced phase transition occurred. The high-pressure phase is a distorted fluorite structure in which the cations and anion vacancies are disordered. The disordered structure is accompanied by the formation of partially amorphous domains. With the release of pressure, the high-pressure phase partially transforms to the amorphous state.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 930467
• Report Number(s): BNL--81219-2008-JA
• Journal Information: Chemical Physics Letters, Journal Name: Chemical Physics Letters Journal Issue: 39544 Vol. 441; ISSN CHPLBC; ISSN 0009-2614
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMORPHOUS STATE
ANIONS
CATIONS
CRYSTAL STRUCTURE
FLUORITE
PHASE TRANSFORMATIONS
PRESSURE RANGE GIGA PA
PYROCHLORE
SCATTERING
VACANCIES
X-RAY DIFFRACTION
national synchrotron light source