High-density β″-alumina with relative density exceeding 98% was obtained by spark plasma sintering (SPS) at 1400 °C for 15 min. X-ray diffraction measurements and scanning electron microscopy demonstrated that the c-axis of the β″-alumina grains oriented along the direction of pressure application during SPS. Na volatilization was well suppressed by encapsulation in a carbon die and a short sintering time. Higher ionic conductivity was observed along the vertical direction than along the direction of pressure application owing to the alignment of the conduction plane in β″-alumina crystals. The highest total conductivity at 25 °C was 1.9 × 10- 2 S·cm- 1.
All Science Journal Classification (ASJC) codes
- 化学 (全般)