Preparation, characterization and thermal diffusivity of γ-LiAlO2

γ-LiAlO2 powder has been prepared by reaction of aqueous LiOH with Al and calcination at 1225 K. Samples of different porosities (10 to 22%) were fabricated by pressing and sintering at temperatures of 1625-1675 K. The sintered samples were characterized by chemical and X-ray analysis. Pore-concentration, -shape, and -orientation were determined by quantitative microstructural analysis. The porosity dependance of the thermal diffusivity was investigated. Over the temperature range from room temperature to 1275 K the thermal conductivity follows an equation of the type lambda=1/(A+BT)+CT3-D. The discrepancy between earlier published data of the thermal conductivity and results from this work is discussed on the background of different production processes for the γ-LiAlO2 powder. Furthermore the linear thermal expansion of γ-LiAlO2 was measured and compared with earlier data. An equation is recommended for the temperature range 293<T<1000 K. (orig./GSCH)