Formation of mixed oxide powders in flames: Part II. SiO sub 2 --GeO sub 2 and Al sub 2 O sub 3 --TiO sub 2

Journal Article · Wed Jul 01 00:00:00 EDT 1992 · Journal of Materials Research; (United States)

DOI:https://doi.org/10.1557/JMR.1992.1870· OSTI ID:7068555

Hung, C; Miquel, P F; Katz, J L ^[1]

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1. Department of Chemical Engineering, The Johns Hopkins University, Baltimore, Maryland 21218 (United States)

SiO{sub 2}--GeO{sub 2} and Al{sub 2}O{sub 3}--TiO{sub 2} mixed oxide powders were synthesized using a counterflow diffusion flame burner. SiCl{sub 4}, GeCl{sub 4}, Al(CH{sub 3}){sub 3}, and TiCl{sub 4} were used as source materials for the formation of oxide particles in hydrogen-oxygen flames. {ital In} {ital situ} particle sizes were determined using dynamic light-scattering. Powders were collected using two different methods, a thermophoretic method (particles are collected onto carbon coated TEM grids) and an electrophoretic method (particles are collected onto stainless steel strips). Their size, morphology, and crystalline form were examined using a transmission electron microscope and an x-ray diffractometer. A photomultiplier at 90{degree} to the argon ion laser beam was used to measure the light-scattering intensity. The formation of the mixed oxides was investigated using Si to Ge and Al to Ti ratios of 3:5 and 1:1, respectively. Heterogeneous nucleation of the SiO{sub 2} on the surface of the GeO{sub 2} was observed. In Al{sub 2}O{sub 3}--TiO{sub 2} mixtures, both oxide particles form at the same temperature. X-ray diffraction analysis of particles sampled at temperatures higher than 1553 K showed the presence of rutile, {gamma}--Al{sub 2}O{sub 3}, and aluminum titanate. Although the particle formation processes for SiO{sub 2}--GeO{sub 2} is very different from that for Al{sub 2}O{sub 3}--TiO{sub 2}, both mixed oxides result in very uniform mixtures.

• DOE Contract Number: FG02-88ER45356
• OSTI ID: 7068555
• Journal Information: Journal of Materials Research; (United States), Vol. 7:7; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
SYNTHESIS
GERMANIUM OXIDES
POWDERS
SILICON OXIDES
TITANIUM OXIDES
CHEMICAL VAPOR DEPOSITION
FLAMES
LIGHT SCATTERING
MIXTURES
PARTICLE SIZE
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL COATING
COHERENT SCATTERING
DEPOSITION
DIFFRACTION
DISPERSIONS
ELECTRON MICROSCOPY
GERMANIUM COMPOUNDS
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
SCATTERING
SILICON COMPOUNDS
SIZE
SURFACE COATING
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication