Solid state sintering of very low and negative thermal expansion ceramics by Spark Plasma Sintering. O. García-Moreno, A. Fernández, R. Torrecillas.2011.

Ceramics International, Volume 37, Issue 3, Pages 1079-1083, 2011. http://www.sciencedirect.com/science/article/pii/S0272884210005146

Lithium aluminosilicate powder precursors of compositions Li₂O:Al₂O₃:SiO₂ as 1:1:2; and 1:1:3.11 were synthesized and sintered by the Spark Plasma Sintering technique. The sintering conditions were adjusted to obtain dense ceramic materials in an attempt to avoid the presence of a glassy phase. XRD and SEM images were employed for composition and microstructure characterization. The coefficient of thermal expansion of the sintered samples was studied down to cryogenic conditions. Rietveld quantification was performed with the use of an external standard. Pure β-eucryptite of different compositions in dense ceramic bodies was obtained with a negative expansion coefficient.