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The System HfO 2 ‐Y 2 O 3 ‐Er 2 O 3
Author(s) -
Andrievskaya Elena R.,
Lopato Lidia M.,
Smirnov Vasily P.
Publication year - 1996
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/j.1151-2916.1996.tb07934.x
Subject(s) - liquidus , crystallization , crystallography , solid solution , hexagonal crystal system , phase (matter) , diffraction , materials science , fluorite , mineralogy , analytical chemistry (journal) , chemistry , thermodynamics , physics , metallurgy , optics , chromatography , organic chemistry
A mathematical model of the liquidus surface based on a reduced polynomial method was proposed for the system HfO 2 ‐Y 2 O 3 ‐Er 2 O 3 . The results of calculations according to this model agree fairly well with the experimental data. Phase equilibria in the system HfO 2 ‐Y 2 O 3 ‐Er 2 O 3 were studied on melted (as‐cast) and annealed samples using X‐ray diffraction (at room and high temperatures) and micro‐structural and petrographic analyses. The crystallization paths in the system HfO 2 ‐Y 2 O 3 ‐Er 2 O 3 were established. The system HfO 2 ‐Y 2 O 3 ‐Er 2 O 3 is characterized by the formation of extended solid solutions based on the fluorite‐type (F) form of HfO 2 and cubic (C) and hexagonal (H) forms of Y 2 O 3 and Er 2 O 3 . The boundary curves of these solid solutions have the minima at 2370°C (15. 5 mol% HfO 2 , 49. 5 mol% Y 2 O 3 ) and 2360°C (10. 5 mol% HfO 2 , 45. 5 mol% Y 2 O 3 ). No compounds were found to exist in the system investigated.