Low‐Temperature Synthesis of Praseodymium‐Doped Ceria Nanopowders

Abstract

Praseodymium‐doped ceria (CeO 2 ) nanopowders have been synthesized via a simple but effective carbonate‐coprecipitation method, using nitrates as the starting salts and ammonium carbonate as the precipitant. The precursors produced in this work are ammonium rare‐earth double carbonates, with a general formula of (NH 4 ) 0.16 Ce 1− x Pr x (CO 3 ) 1.58 ·H 2 O (0 < x ≤ 0.20), which directly yield oxide solid solutions on thermal decomposition at a very low temperature of ∼400°C. Praseodymium doping causes a gradual contraction of the CeO 2 lattice, because of the oxidation of Pr 3+ to smaller Pr 4+ , and suppresses crystallite coarsening of the oxides during calcination. Dense ceramics have been fabricated from the thus‐prepared nanopowders via pressureless sintering for 4 h at a low temperature of 1200°C.