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Synthesis of Pb(Mg 1/3 Nb 2/3 )O 3 by Self‐Assembled Colloidal Aggregates
Author(s) -
Trefalt Gregor,
Malic̆ Barbara,
Kušc̆er Danjela,
Holc Janez,
Kosec Marija
Publication year - 2011
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.1551-2916.2011.04443.x
Subject(s) - suspension (topology) , pyrochlore , colloid , oxide , materials science , chemical engineering , acetone , niobium , aqueous suspension , niobium oxide , aqueous solution , particle size , inorganic chemistry , particle (ecology) , lead oxide , perovskite (structure) , phase (matter) , chemistry , metallurgy , organic chemistry , oceanography , mathematics , homotopy , geology , pure mathematics , engineering
We developed a new, simple method to prepare pure perovskite Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) from an aqueous suspension in a single annealing step. In this synthesis it is crucial to suppress the reaction between PbO and Nb 2 O 5 , which leads to secondary pyrochlore Pb x Nb y O z phases. Our method is based on the designed arrangement of particles of the starting compounds. The self‐assembly of the colloidal aggregates was governed by particle surface charge, which was adjusted by the suspension pH. At pH below 11.8 particle–particle interactions lead to close contacts between lead oxide and niobium oxide particles in the suspension as well as in the dried powders, whereas at pH above 11.8 close contacts between lead and niobium oxide particles are avoided. The suspensions of the starting powders were prepared at pH 10.0, 11.4, 12.5, and in acetone. After heating of the dried suspension with the pH set at 12.5 at 900°C, a pure perovskite PMN powder was obtained. On the contrary, the powders prepared from the pH 11.4, 10.0, and acetone suspensions still contained the detrimental pyrochlore phase after heating at 900°C. The properties of the ceramics prepared from the pH 12.5 suspension are superior in comparison with the other samples.