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Ferroelectrics of Ultrafine Particle Size: II, Grain Growth Inhibition Studies
Author(s) -
HARKULICH THEODORE M.,
MAGDER JULES,
VUKASOVICH MARK S.,
LOCKHART ROBERT J.
Publication year - 1966
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1966.tb13266.x
Subject(s) - materials science , barium titanate , grain size , particle size , sintering , grain growth , curie temperature , mineralogy , dielectric , particle (ecology) , particle size distribution , composite material , tantalum , metallurgy , ceramic , chemical engineering , condensed matter physics , chemistry , physics , oceanography , optoelectronics , ferromagnetism , geology , engineering
Inhibition of grain growth in pure, fine‐particle‐size barium titanate bodies by coating the surfaces of the barium titanate particles with tantalum oxide was so effective that doping with a sintering aid was necessary for densification of the bulk material at temperatures below the melting point. A correlation, which was independent of starting particle size, was established between inhibitor concentration and final grain size of the fired bodies. Barium titanate bodies of predetermined grain size not larger than 2000 A were obtained even with extended firing schedules. In the smallest grain sizes, the Curie point was shifted below the measured temperature range, and hysteresis losses were reduced markedly. The dielectric constant had a smooth variation from approximately 3000 at room temperature to 800 at 180°C.