Zhang Ping, Zhao Yonggui, Li Lingxia
School of Electronic and Information Engineering, Tianjin University, Tianjin 300072, China.
Phys Chem Chem Phys. 2015 Jul 14;17(26):16692-8. doi: 10.1039/c5cp02204e.
(Nd1-xLax)NbO4 ceramics were prepared via a conventional solid-state reaction route and the correlations among bond ionicity, lattice energy, phase stability and microwave dielectric properties were investigated. The diffraction patterns showed that the (Nd1-xLax)NbO4 ceramics possessed a monoclinic fergusonite structure. The chemical bond ionicity, bond covalency and lattice energy were calculated using the empirical method. The phase structure stability varied with the lattice energy which resulted due to the substitution content of La(3+) ions. With the increase of La(3+) ion contents, the decrease of Nd/La-O bond ionicity was observed, which could be attributed to the electric polarization. εr has a close relationship with the Nd/La-O bond covalency. The increase of the Q × f values and τf values could be attributed to the change in the lattice energy. The microwave dielectric properties of (Nd1-xLax)NbO4 ceramics with a monoclinic fergusonite structure were strongly dependent on the chemical bond ionicity, bond covalency and lattice energy.
通过传统的固态反应路线制备了(Nd1-xLax)NbO4陶瓷，并研究了键离子性、晶格能、相稳定性和微波介电性能之间的相关性。衍射图谱表明，(Nd1-xLax)NbO4陶瓷具有单斜磷钇矿结构。采用经验方法计算了化学键离子性、键共价性和晶格能。相结构稳定性随La(3+)离子取代含量导致的晶格能而变化。随着La(3+)离子含量的增加，观察到Nd/La-O键离子性降低，这可归因于极化。εr与Nd/La-O键共价性密切相关。Q×f值和τf值的增加可归因于晶格能的变化。具有单斜磷钇矿结构的(Nd1-xLax)NbO4陶瓷的微波介电性能强烈依赖于化学键离子性、键共价性和晶格能。
