A study was carried out on the synthesis of CuAlO2 at temperatures below 1000 1C, using a simple approach based on mechanical mixing of
chemically precipitated CuO and Al(OH)3 nanoparticles. Synthesis of precursor powders was achieved at low temperatures (o100 1C) via
precipitation from their corresponding aqueous solutions. After drying at room temperature, precursors were mixed in equimolar ratios by a
combination of ball milling and sonication. Green pellets were obtained by filtration casting of the mixed powder slurry followed by dry
compaction. X-ray diffraction study showed that the single phase CuAlO2 samples with high crystallinity formed only after 5 h of firing at 900 1C
under flowing nitrogen. Electron microscopy images revealed a loosely packed microstructure with high surface area consisting of nanosized
grains after the heat treatment. The achieved relative density was 45% of the theoretical density. The crystallite size was estimated to be 39 nm
and the specific surface area of the sintered sample was measured as 9.67 m2
/g. The bandgap was calculated as 3.07 eV with a transmittance of
60% in the visible region. The measured electrical conductivity was 4 103 mS/cm at room temperature and showed an increase with
increasing measurement temperature, which indicates semiconducting behavior. The conductivity was shown to increase by an order of
magnitude with a higher degree of densification by sintering at 1150 1C.