Fabrication of Nd:Y2O3 transparent ceramics by pulsed compaction and sintering of weakly agglomerated nanopowders

In this paper the fabrication of dense, optically transparent ceramics by compaction and sintering of nanosized Y2O3 powders, doped by different Nd2O3 content (1.0 and 3.3 mol%) is investigated. The sintering temperature was decreased substantially, and there were no extra additives inserted into basic oxide due to high nanosystem activity. The as synthesized powder was transformed from monoclinic to cubic modification by the preliminary calcination in air at 800 °C in order to avoid cracking during sintering. This phase transformation of the starting powder, annealing of the compacts in air (1200 °C) and sintering in vacuum for 1 h at 1700 °C allowed to fabricate optically transparent ceramics with well-formed boundaries, average crystalline size of 30–40 μm and vanishingly small porosity with pore size less than 0.5 μm.