论文部分内容阅读
The local structure of an alteative Pb(Zn1/3Nb2/3)O3-based perovskite ceramic is investigated.The 0.07BaTiO3-0.93Pb(Zn1/3Nb2/3)O3 ceramic is synthesized using a combination of Zn3Nb2Os B-site precursor and BaTiO3 perovskite phase stabilizer.Then,x-ray absorption spectroscopy and density functional theory are employed to calculate the local structure configuration and formation energy of the prepared samples.Ba2+ is found to replace Pb2+ in A-site with Zn2+ occupying B-site in Pb(Zn1/3Nb2/3)O3,while in the neighboring structure,Ti4+replaces Nb5+ in B-site with Pb2+ occupying A-site.With the substitution of BaTiO3 in Pb(Zn1/3Nb2/3)O3,the bond length between Zn2+ and Pb2+ is longer than that of the typical perovskite phase of Pb(Zn1/3Nb2/3)O3.This indicates the key role of BaTiO3 in decreasing the steric hindrance of Pb2+ lone pair,and the mutual interactions between Pb2+ lone pair and Zn2+ and the formation energy is seen to decrease.This finding of the formation energy and local structure configuration relationship can further extend a fundamental understanding of the role of BaTiO3 in stabilizing the perovskite phase in PbZn13Nb23O3-based materials,which in tu will lead to an improved preparation technique for desired electrical properties.