PREPARATION OF B-SITE ORDERED COMPLEX PEROVSKITE SrYb_(0.5)Nb_(0.5)O_3 BY AMORPHOUS CITRATE PROCESS

摘要

Amorphous citrate process has been used to synthesize the complex perovskite SrYb_(0.5)Nb_(0.5)O_3 (SYN) powder. Citrate-nitrate gels were produced at room temperature by first reacting NbCl_5 with aqueous solution of NH_4OH to produce Nb(OH)_5 and then mixing the filtered Nb(OH)_5 with strontium nitrate and yitterbium nitrate in citric acid aqueous solution. The precursor ash was produced by auto ignition of the dehydrated precursor gel at 200 deg C. Finely crystallized SYN powder could be obtained by thermal decomposition of the citrate precursors ash at temperature as low as 1000 deg C. X-ray diffraction, Infra-red transmittance spectroscopy and electron microscopy have been used to characterize the precursors and annealed materials synthesized by citrate process. The citrate process is very promising and simple for preparing complex perovskite SrYb_(0.5)Nb_(0.5)O_3.