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Synthesis of Nanocrystalline Lithium Zinc Ferrites Using Polyacrylic Acid, and Their Initial Densification
Author(s) -
Cho Yong S.,
Burdick Ver L.,
Amarakoon Vasantha R. W.
Publication year - 1999
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.1151-2916.1999.tb01932.x
Subject(s) - nanocrystalline material , materials science , polyacrylic acid , activation energy , spinel , nanoparticle , chemical engineering , particle size , zinc , lithium (medication) , grain boundary , diffusion , grain size , nuclear chemistry , analytical chemistry (journal) , microstructure , metallurgy , nanotechnology , composite material , chemistry , organic chemistry , thermodynamics , medicine , physics , endocrinology , engineering , polymer
A chemical synthesis technique that uses polyacrylic acid (PAA) to prepare nanocrystalline Li 0.3 Zn 0.4 Fe 2.3 O 4 was investigated. Phase‐pure spinel that had an average particle size of ∼13 nm was synthesized at a low temperature (450°C) for 30 min. The average particle size was dependent on the firing temperature and amounts of PAA and Bi 2 O 3 . The combustion reaction of PAA was believed to be the main reason for the low‐temperature synthesis of nanocrystalline lithium zinc (LiZn) ferrites. In addition, a chelating tendency was observed, via infrared (IR) spectroscopy, in the dried gel precipitates that were prepared at a low pH (∼2). The initial densification behavior of the nanopowder compacts was studied using linear‐shrinkage data. Densification of the nanopowder without Bi 2 O 3 started at low temperatures (∼400°C). The addition of Bi 2 O 3 to the nanopowder noticeably did not contribute to reducing the initial densification temperature. This result was supported by the activation‐energy calculation for the initial densification. Compared to an activation energy of 280 kJ/mol for grain‐boundary diffusion of the nanopowder without Bi 2 O 3 , a higher value (430 kJ/mol) was obtained in the case of the 3 wt% Bi 2 O 3 ‐containing nanopowder.