The effect of the synthesis conditions of yttrium oxide powder doped with neodymium on morphology

The dependence of shape and particle size of Nd-doped yttrium oxide powder on the synthesis method was investigated, covering homogeneous and heterogeneous co-precipitation. For the homogeneous co-precipitation method, the dependence of shape and particle size of Nd-doped yttrium oxide powder on the concentration of the initial salts in a solution, the ratio of concentrations of yttrium ions to the precipitator in the solution, the aging time of the precipitate during synthesis, and synthesis temperatures were investigated. It was found that for homogeneous co-precipitation the particle shape did not change during the transition from the precursor to synthesized yttrium oxide: spherical particles were formed. The nature of the precursor was established by infrared spectrometry and X-ray fluorescence analysis. The precursor was X-ray amorphous, of bicarbonate nature. The particle size decreased by 10-20% during the transition from the precursor to the synthesized yttrium oxide. For the heterogeneous co-precipitation method, the dependence of shape and particle size on precipitator nature (ammonia solution and ammonium bicarbonate solution) were investigated. Besides, the effect of the concentration of the initial salts and the synthesis temperature on the shape and particle size) was studied. It was found that for heterogeneous co-precipitation, regardless of the precipitator nature, the particle shape did not change after conversion from the precursor to the synthesized yttrium oxide. Needle-shaped particles collected in agglomerates were obtained with ammonia as the precipitator. Plate-shaped particles were obtained with a solution of ammonium bicarbonate as the precipitator. The precursor nature was established by infrared spectrometry and X-ray phase analysis. The precursor was X-ray amorphous, of bicarbonate nature, if a solution of ammonium bicarbonate was used as the precipitator. The precursor was a mixture of hydrates of yttrium oxohydroxonitrates, if ammonia was used as the precipitator. The particle size obtained by the co-precipitation method with ammonia as precipitator did not change during the conversion from the precursor to the synthesized yttrium oxide, while the particle size obtained by the co-precipitation method with ammonium bicarbonate as precipitator decreased by 2 times.