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Role of Water Vapor in Crystallite Growth and Tetragonal‐Monoclinic Phase Transformation of ZrO 2
Author(s) -
MURASE YOSHIO,
KATO ETSURO
Publication year - 1983
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.1151-2916.1983.tb10016.x
Subject(s) - tetragonal crystal system , monoclinic crystal system , crystallite , materials science , phase (matter) , mineralogy , crystallography , chemical engineering , analytical chemistry (journal) , chemistry , crystal structure , metallurgy , organic chemistry , engineering
The role of water vapor in crystallite growth and the tetragonal‐to‐monoclinic phase transformation of ZrO 2 was studied using three specially prepared samples: an ultrafine powder of monoclinic ZrO 2 obtained by hydrolysis of ZrOCI 2 , an aggregated powder of tetragonal ZrO 2 obtained by thermal decomposition of Zr(OH) 4 under reduced pressure, and an ultrafine powder of tetragonal ZrO 2 obtained by thermal decomposition of zirconyl acetate dispersed in caramel. The samples were heat‐treated up to 1000°C in dry and wet atmospheres saturated with water vapor at 90°C. It was found that water vapor markedly accelerated crystallite growth for both monoclinic and tetragonal ZrO 2 and facilitated the tetragonal‐to‐monoclinic phase transformation. Water vapor increases surface diffusion and thus enhances crystallite growth and decreases surface energy, which leads to stabilization of the tetragonal phase.