Direct Precipitation of Spinel-Type Zn(Fe, Ga)2O4 Solid Solutions from Aqueous Solutions at 90°C: Influence of Iron Valence of Starting Salt on Their Crystallite Growth
✍ Scribed by Masanori Hirano; Shiro Okumura; Yasunori Hasegawa; Michio Inagaki
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 274 KB
- Volume
- 168
- Category
- Article
- ISSN
- 0022-4596
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✦ Synopsis
Spinel-type solid solutions in the whole range of compositions between ZnGa 2 O 4 and ZnFe 2 O 4 were directly precipitated as nanoparticles by dropping the starting mixed solutions of zinc sulfate, gallium sulfate, and either divalent iron chloride or trivalent iron nitrate into aqueous ammonia at 901C. Direct precipitation of nanosized spinel-type Zn(Ga,Fe)O 4 solid solutions was also achieved by aging the mixed solutions in the presence of either urea or hexamethylenetetramine at 901C except for one case (i.e., aging the solutions using trivalent iron salt in the presence of urea). With increased iron content in the spinel-type solid solution precipitates, their crystallite size decreased when trivalent iron salt was used, but increased when divalent iron salt was used. Change of lattice parameter a 0 of the spinel-type solid solutions was confirmed to follow the Vegard's Law.