1Program in Applied Physics, Faculty of Science, Maejo University, Chiang Mai 50290, Thailand 2Synchrotron Light Research Institute, Ratchasima 30000, Thailand 3School of Physics, Institute of Science, and NANOTEC-SUT Center of Excellence on Advanced Functional Nanomaterials, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
Abstract：The local structure of an alternative Pb(Zn$_{1/3}$Nb$_{2/3}$)O$_{3}$-based perovskite ceramic is investigated. The 0.07BaTiO$_{3}$-0.93Pb(Zn$_{1/3}$Nb$_{2/3}$)O$_{3}$ ceramic is synthesized using a combination of Zn$_{3}$Nb$_{2}$O$_{8}$ $B$-site precursor and BaTiO$_{3}$ 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. Ba$^{2+}$ is found to replace Pb$^{2+}$ in $A$-site with Zn$^{2+}$ occupying $B$-site in Pb(Zn$_{1/3}$Nb$_{2/3}$)O$_{3}$, while in the neighboring structure, Ti$^{4+}$ replaces Nb$^{5+}$ in $B$-site with Pb$^{2+}$ occupying $A$-site. With the substitution of BaTiO$_{3}$ in Pb(Zn$_{1/3}$Nb$_{2/3}$)O$_{3}$, the bond length between Zn$^{2+}$ and Pb$^{2+}$ is longer than that of the typical perovskite phase of Pb(Zn$_{1/3}$Nb$_{2/3}$)O$_{3}$. This indicates the key role of BaTiO$_{3}$ in decreasing the steric hindrance of Pb$^{2+}$ lone pair, and the mutual interactions between Pb$^{2+}$ lone pair and Zn$^{2+}$ 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 BaTiO$_{3}$ in stabilizing the perovskite phase in PbZn$_{13}$Nb$_{23}$O$_{3}$-based materials, which in turn will lead to an improved preparation technique for desired electrical properties.
2017, Vol. 34 
