Highly Dense, Transparent α‐ Al 2 O 3 Ceramics From Ultrafine Nanoparticles Via a Standard SPS Sintering

Using discrete, ultrafine alumina, highly dense transparent (71% real in‐line transmission, RIT , λ = 640 nm) ceramics were achieved with grain size as small as 260 nm using standard SPS sintering. We show that use of La 3+ as a dopant greatly reduces sensitivity to the sintering temperatures. Transparent alumina were achieved in a large range of sintering temperatures, 1140°C < T < 1200°C, thus providing better reliability and flexibility into the fabrication of large sintered transparent ceramic bodies.