Preparation of monodispersed yttrium hydroxycarbonate spheres by homogeneous precipitation

Technical Report · Mon Jun 01 04:00:00 EDT 1987

OSTI ID:6427782

Verlinden, M C

Highly monodisperse, submicrometer size, spherical particles of yttrium hydroxycarbonate were prepared by homogeneous precipitation from a yttrium nitrate-urea solution. The precipitant, CO2, was generated by thermal decomposition of the urea when the solution was heated to 90 to 100C. The amorphous precipitate particles, which had the chemical formula, Y(CO3)OH.H2O, suffered a 30% weight loss when calcined to polycrystalline Y2O3, but maintained their sphericity. Spherical particles were obtained only over a limited range of reactant ratios. Particle sizes ranged from 0.1 m to 0.7 m and, of the seventeen different run conditions for which discrete spherical particles were obtained, only one run produced spheres whose diameters had a geometric standard deviation greater than 1.10. The growth of the particles, followed by in situ laser light scattering during the precipitation reaction, was best described by a model based on the decomposition of urea as the rate-limiting step in the process.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6427782
• Report Number(s): IS-T-1234; ON: DE87013071
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
AMIDES
CALCINATION
CARBONIC ACID DERIVATIVES
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
LIGHT SCATTERING
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
PRECIPITATION
PRODUCTION
PYROLYSIS
SCATTERING
SEPARATION PROCESSES
SIZE
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
UREA
YTTRIUM COMPOUNDS
YTTRIUM OXIDES