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Densification and Crystallization of Lead Titanate Aerogels
Author(s) -
Löbmann Peer,
Glaubitt Walther,
Fricke Jochen
Publication year - 1997
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.1151-2916.1997.tb03168.x
Subject(s) - materials science , crystallization , gas pycnometer , tetragonal crystal system , chemical engineering , transmission electron microscopy , supercritical fluid , thermogravimetric analysis , lead titanate , shrinkage , amorphous solid , porosity , composite material , mineralogy , crystallography , ferroelectricity , nanotechnology , crystal structure , chemistry , optoelectronics , organic chemistry , dielectric , engineering
Crack‐free monolithic lead titanate (PbTiO 3 , or PT) aerogels were prepared via a sol‐gel process and drying in supercritical carbon dioxide. The material was characterized by thermogravimetric analysis, dilatometry, helium pycnometry, and X‐ray diffraction. Skeletal densification was the main reason for the observed shrinkage of the heat‐treated porous material at temperatures <450°C. The transition (at temperatures of 500°‐600°C) from an amorphous state to the crystalline (tetragonal) PT was accompanied by significant particle coarsening, as revealed by transmission electron microscopy. Nitrogen adsorption measurements confirmed that crystallization was preceded by the formation of interparticle necks.