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Morphology of Zirconia Synthesized Hydrothermally from Zirconium Oxychloride
Author(s) -
Mottet Bruno,
Pichavant Michel,
Bény JeanMichel,
Alary JeanAndré
Publication year - 1992
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.1151-2916.1992.tb05605.x
Subject(s) - ostwald ripening , cubic zirconia , monoclinic crystal system , precipitation , zirconium , materials science , dissolution , hydrothermal circulation , morphology (biology) , crystal (programming language) , hydrothermal synthesis , chemical engineering , mineralogy , crystal growth , crystal structure , crystallography , nuclear chemistry , chemistry , nanotechnology , metallurgy , ceramic , geology , paleontology , programming language , physics , meteorology , computer science , engineering
Monoclinic zirconia has been synthesized hydrothermally from zirconium oxychloride in the range 20–100 MPa, 250–650°C, for run duration from 20 to 100 h and in the presence of NaOH, Na 2 CO 3 , Na 2 SO 4 , NH 4 F, HNO 3 , and H 2 SO 4 additives. Isometric, platelike, and elongated crystal morphologies were obtained depending on the additive. Both spherulitic and isolated textures were encountered with H 2 SO 4 . Growth of isometric crystals follows a general dissolution–precipitation mechanism. For H 2 SO 4 , two growth steps were identified: an early spherulitic step followed by an isolated crystals step resulting from Ostwald ripening of preexisting spherulites. The formation of spherulites is consistent with the specific properties of the sulfuric hydrothermal medium.