Origin of solid-state activated sintering in Bi{sub 2}O{sub 3}-doped ZnO

Journal Article · Thu Apr 01 04:00:00 EST 1999 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1999.tb01853.x· OSTI ID:347464

Luo, J; Wang, H; Chiang, Y M ^[1]

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1. Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Materials Science and Engineering

Activated sintering in Bi{sub 2}O{sub 3}-doped ZnO has been studied with emphasis on the mechanistic role of intergranular amorphous films. The atomic-level microstructures and bismuth solute distributions in doped powders have been investigated using high-resolution electron microscopy and scanning transmission electron microscopy. Densification is observed to be significant below the bulk eutectic temperature in the presence of Bi{sub 2}O{sub 3} concentrations as low as 0.58 mol %. Transmission electron microscopy of as-calcined and sintered powders shows that significant neck growth and particle coarsening occur in the solid state. Intergranular amorphous films of {approximately}1 nm thickness, terminating in wetting menisci at sinter-necks, are observed to form concurrently with the onset of activated sintering. In a few instances, amorphous films are also observed at surfaces of the ZnO particles. These films appear to be the free-surface counterpart to equilibrium-thickness intergranular films. Activated sintering in this binary system is attributed to rapid mass transport through subeutectic, equilibrium-thickness intergranular films, with the amorphous phase also providing capillary pressure.

• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: FG02-87ER45307
• OSTI ID: 347464
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 4 Vol. 82; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BISMUTH OXIDES
BULK DENSITY
CHEMICAL COMPOSITION
DOPED MATERIALS
MICROSCOPY
MICROSTRUCTURE
SINTERING
ZINC OXIDES