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Colloidal Processing and Characterization of Aluminum‐Doped Lanthanum Oxyapatite, La 10 AlSi 5 O 26.5
Author(s) -
Santacruz Isabel,
PorrasVázquez José M.,
Losilla Enrique R.,
Nieto M. Isabel,
Moreno Rodrigo,
Aranda Miguel A.G.
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.1551-2916.2010.04074.x
Subject(s) - materials science , sintering , microstructure , chemical engineering , ceramic , electrolyte , lanthanum , solid oxide fuel cell , compaction , raw material , oxide , characterization (materials science) , particle size , composite material , metallurgy , nanotechnology , inorganic chemistry , electrode , chemistry , organic chemistry , engineering
Lanthanum apatite is one of the most promising materials as electrolytes for intermediate‐temperature solid oxide fuel cells (IT‐SOFC), those operating close to 700°C. The complexity of microstructures, composition, and geometries of SOFC devices, make it necessary to have a precise control of processing parameters to obtain the desired combination of properties. This work involves the preparation and optimization of La 10 AlSi 5 O 26.5 materials by reaction sintering of the raw materials (La 2 O 3 , Al 2 O 3 , and SiO 2 ) to be used as IT‐SOFCs electrolytes. Homogeneous mixed suspensions of those ceramic oxides were prepared. A heterocoagulation process was followed for ensuring a better reactivity during sintering. All the parameters involved in the process, such as deflocculant content, particle size of the initial powders, sonication time of the mixed suspensions, compaction, and sintering cycle were optimized. The effect of all these parameters were studied and discussed. Finally, La 10 AlSi 5 O 26.5 electrolytes with density values of ∼88% of the theoretical density and total conductivities of 1.7 × 10 −2 S/cm at 700°C were obtained. This study opens a path for the preparation of concentrated suspensions for obtaining dense thin films.