Synthesis of Yb：Lu3Al5O12nano powders with the reverse strike co-precipitation method：influence of decomposition of NH4HCO3

Yb：Lu3Al5O12 （Yb：LuAG） nano powders were synthesized with the co-precipitation method from cation （Lu3＋, Yb3＋, Al3＋） solution of different concentrations using NH4HCO3 as the precipitant. The influence of cation concentration on the morphology and purity of the calcined powders was studied. Contrary to the conventional suggestion that recommends thin solution to obtain loosely agglomerated nano powders, results showed that thin cation （Lu＋Yb＋Al） concentration ≤0.08 mol/L led to formation of Al2O3 and LuAP impurities in the obtained nano powders. By means of Tg/（DTA）, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, the cause was revealed to be re-dissolution of Lu at high pH value that resulted from the decomposition of NH4HCO3.（Lu＋Yb＋Al） concentration of ~0.24 mol/L was recommended to achieve pure Yb：LuAG nano powders. Transparent Yb：LuAG ceramics were fabricated with the prepared Yb：LuAG nano powders. The transmittance around 800 nm was 77.5%.