科研之友
微信
新浪微博
Facebook
分享链接
摘要
A molten salt method was developed for the synthesis of ACeO(3)(A=Sr, Ba) with perovskite structure at 750 degrees C(SrCeO3) and 850 degrees C(BaCeO3) in the eutectic NaCl-KCl. The synthetic temperature was much lower than that of the conventional method(generally>1000 degrees C). The structure and morphology of the product were characterized by means of X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM) and transmission electron microscopy(TEM). The results show that the synthesized octahedral SrCeO3 crystallizes in the orthorhombic system with the unit cell parameters of a=0.85855 nm, b=0.61523 nm, c=0.60059 nm, and the synthesized cuboid BaCeO3 crystallizes in the cubic system with the unit cell parameter of a=0.43962 nm. The result of X-ray photoelectron spectroscopy(XPS) analysis indicates that both Ce4+ and Ce3+ exist in the two structures, and the Ce4+/Ce3+ peak area ratios for SrCeO3 and BaCeO3 are 1.93 and 2.12, respectively. Meanwhile, the adsorbed/lattice oxygen ratios(1.87 for SrCeO3 and 3.04 for BaCeO3) indicate the existence of a lot of oxygen vacancies in the structures of SrCeO3 and BaCeO3, which indicates a far-reaching significance to study the corresponding physicochemistry performance.
- 出版日期2015-6
- 单位北京科技大学
