Preventing hydrolysis of BaTiO3 powders during aqueous processing and of bulk ceramics after sintering

authors	Olhero, SM; Kaushal, A; Ferreira, JMF
nationality	International
journal	JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
author keywords	Barium titanate; Ferroelectrics; Aqueous colloidal processing; Surface treatment
keywords	BARIUM-TITANATE POWDERS; POLYMERIC STABILIZATION; AMMONIUM-SALT; SUSPENSIONS; DISPERSION; MEDIA; ACID; PH
abstract	This present article addresses the reactive behaviour of barium titanate (BaTiO3, hereafter referred to as BT) with water either in powder form or as bulk ceramics. Chemisorbing a suitable phosphate-based protective agent at the surface of BT particles prevented hydrolysis reactions and made aqueous processing of BT a safe and viable route. Highly concentrated (50 vol.%) fluid and long term stable suspensions could be easily prepared from surface treated BT particles, contrasting with the poor stability and high viscosity of slurries derived from the as received powders. For aqueous suspensions, the course of hydrolysis reactions was monitored through changes in pH and concentrations of leached ionic species along ageing time. For bulk ceramics, the extent of hydrolysis reactions was assessed through the microstructural changes occurred at polished surfaces without and with surface treatment, which have been kept in contact with water for a certain time period. (C) 2015 Elsevier Ltd. All rights reserved.
publisher	ELSEVIER SCI LTD
issn	0955-2219
year published	2015
volume	35
issue	9
beginning page	2471
ending page	2478
digital object identifier (doi)	10.1016/j.jeurceramsoc.2015.03.007
web of science category	Materials Science, Ceramics
subject category	Materials Science
unique article identifier	WOS:000354505300005