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Hydrothermal Synthesis and Low‐Temperature Sintering of Zinc Gallate Spinel Fine Particles
Author(s) -
Hirano Masanori,
Sakaida Naoshi
Publication year - 2002
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.1151-2916.2002.tb00236.x
Subject(s) - spinel , zinc , sintering , aqueous solution , hydrothermal circulation , gallate , materials science , phase (matter) , nuclear chemistry , stoichiometry , hydrothermal synthesis , inorganic chemistry , chemical engineering , chemistry , metallurgy , organic chemistry , engineering
Nanosized powders of single‐phase zinc gallate (ZnGa 2 O 4 ) spinel were hydrothermally synthesized from solutions in the presence of NaOH over the pH range of 1.9 to 7.0 and from solutions above pH 7.0, i.e., the very basic medium (pH of 13.85), by removing the residual ZnO phase by washing with aqueous H 2 SO 4 from the precipitate mixtures of zinc gallate spinel particles and ZnO. A very wide compositional range (Zn/2Ga = 0.705–1.157) of zinc gallate spinel solid solutions could be hydrothermally synthesized in the form of nanosized particles from acid and very basic mediums (pH of 2.4–13.85) in the presence of NaOH. These hydrothermally synthesized spinel powders showed good sinterability and almost full densification at 1100°C for 1 h. Dense sintered bodies consisting of single‐phase zinc gallate spinel were fabricated at 1100°C using zinc gallate spinel powders having almost stoichiometric composition formed from the solution at pH 9.95 in the presence of aqueous ammonia.