Pressure-temperature phase diagram of zirconia

Journal Article · Sun Sep 01 04:00:00 EDT 1985 · J. Am. Ceram. Soc.; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1985.tb15817.x· OSTI ID:6466623

Block, S; da Jornada, J A.H.; Piermarini, G J

The pressure-temperature phase diagram of zirconia was determined by optical microscopy and X-ray diffraction techniques using a diamond anvil pressure cell. At room temperature, monoclinic ZrO/sub 2/ transforms to a tetragonal phase (tII) which is related to the high-temperature tetragonal structure (tI). The transformation pressure exhibits hysteresis and is cycle dependent. At room temperature, the initial transformation pressure for the monoclinic-tII transition on a virgin monoclinic crystal can be as high as 4.4 GPa; on subsequent cycling the transition pressure ultimately lowers to 3.29 + or 0.06 GPa. The pressure for the reverse transition is essentially constant at 2.75 + or - 0.06 GPa. At pressures > 16.6 GPa, the tII form transforms to the orthorhombic cotunnite (PbCl/sub 2/) structure. With increasing temperature, the tII form transforms to the high-temperature tetragonal phase. For increasing P and T, the monoclinic-tI-tII triple point is located at T = 596/sup 0/ + or - 18/sup 0/C and P = 2.26 + or - 0.28 GPa, whereas for decreasing P and T, the triple point is found at T = 535/sup 0/ + or - 25/sup 0/C and P = 1.7 + or - 0.28 GPa.

• Research Organization: Center for Materials Science, National Bureau of Standards, Gaithersburg, Maryland
• OSTI ID: 6466623
• Journal Information: J. Am. Ceram. Soc.; (United States), Journal Name: J. Am. Ceram. Soc.; (United States) Vol. 68:9; ISSN JACTA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
CHALCOGENIDES
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
CRYSTALLOGRAPHY
DIAGRAMS
DIFFRACTION
MICROSCOPY
MONOCLINIC LATTICES
OPTICAL MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PHASE DIAGRAMS
PHASE STUDIES
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PRESSURE EFFECTS
SCATTERING
TEMPERATURE EFFECTS
TETRAGONAL LATTICES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
X-RAY DIFFRACTION
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES