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In‐situ determination of the HfO 2 –Ta 2 O 5 ‐temperature phase diagram up to 3000°C
Author(s) -
McCormack Scott J.,
Tseng KuoPin,
Weber Richard J. K.,
Kapush Denys,
Ushakov Sergey V.,
Navrotsky Alexandra,
Kriven Waltraud M.
Publication year - 2019
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.16271
Subject(s) - liquidus , phase diagram , solidus , analytical chemistry (journal) , diffraction , thermodynamics , materials science , phase (matter) , tantalum , chemistry , optics , metallurgy , physics , organic chemistry , alloy , chromatography
The previously unknown experimental HfO 2 –Ta 2 O 5 ‐temperature phase diagram has been elucidated up to 3000°C using a quadrupole lamp furnace and conical nozzle levitator system equipped with a CO 2 laser, in conjunction with synchrotron X‐ray diffraction. These in‐situ techniques allowed the determination of the following: (a) liquidus, solidus, and invariant transformation temperatures as a function of composition from thermal arrest experiments, (b) determination of equilibrium phases through testing of reversibility via in‐situ X‐ray diffraction, and (c) molar volume measurements as a function of temperature for equilibrium phases. From these, an experimental HfO 2 –Ta 2 O 5 ‐temperature phase diagram has been constructed which is consistent with the Gibbs Phase Rule.