Accession Number:

AD0293847

Title:

ULTRA-FINE PARTICLE SIZE FERROELECTRICS

Descriptive Note:

Corporate Author:

HORIZONS RESEARCH INC CLEVELAND OH

Personal Author(s):

Report Date:

1962-11-15

Pagination or Media Count:

1.0

Abstract:

Barium titanate was produced by controlled pyrolysis of barium titanyl oxalate. By this technique, high purity stoichiometric material was obtained in narrow size cuts ranging as low as 0.05 microns. A study of X-ray diffraction patterns as a function of particle size gave a qualitative correlati n with the electr n micrograph measurements, minimizing grain growth on firing so that 1-2 micron size particles yielded grains 3-5 microns, and .05 micron particles gave 1-2 micron grains. Tantalum oxide used as an in i it r dep ited on the surface of deflocculated barium titanate from colloidal solution was found to effect a dramatic inhibition of grain growth in the fired ceramic, even over prolonged vitrification periods. The net result is a general smoothing of the temperature variation from -40 to 180 C. Precipitation syntheses of barium titanate, based on the hydrolysis of organic titanates in barium hydroxide, were systematically studied. Electron micrographs showing detailed grain structure were obtained by polishing, deep etching, and replicating bodies containing crystallites smaller than 5000 Angstroms. X-ray fluorescence was used on a preliminary basis to check BaOTiO2 ratios in materials made in this laboratory. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE