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Influence of Ammonia on Properties of Nanocrystalline Barium Titanate Particles Prepared by a Hydrothermal Method
Author(s) -
Moon San,
Lee HyunWook,
Choi ChangHak,
Kim Do Kyung
Publication year - 2012
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.1551-2916.2012.05163.x
Subject(s) - anatase , nanocrystalline material , amorphous solid , materials science , chemical engineering , x ray photoelectron spectroscopy , hydrothermal circulation , ammonia , tetragonal crystal system , barium titanate , hydrothermal synthesis , inorganic chemistry , transmission electron microscopy , particle (ecology) , mineralogy , nanotechnology , chemistry , ceramic , crystallography , metallurgy , crystal structure , catalysis , organic chemistry , oceanography , photocatalysis , geology , engineering
The influence of ammonia on BaTiO 3 particles prepared via hydrothermal synthesis is discussed. Two kinds of Ti ‐precursors, amorphous (with ammonia) and anatase (without ammonia), are synthesized by a hydrolysis reaction using Ti ‐butoxide as the starting material. Amorphous Ti ‐precursors are found to be excellent for this purpose and offer several advantages over anatase. Superior tetragonal properties of BaTiO 3 powders with more uniform particle sizes can be achieved at 200°C after 24 h using amorphous Ti ‐precursors. X ‐ray photoelectron spectroscopy was carried out on both types of Ti ‐precursor, and a decrease in H 2 O adsorption on the amorphous Ti ‐precursors is confirmed. It is considered that the reduction in H 2 O adsorption on the Ti ‐precursors results from the shielding effects of ammonia and is attributed to a decreased formation of intragranular pores in the BaTiO 3 particles. These suggested mechanisms are clarified by the results of in situ transmission electron microscopy observations and density measurements of the hydrothermally synthesized BaTiO 3 .