Zubarev J Y, Chang S-H, Lin C, Boldyrev N A, Pavlenko A V, Nazarenko A V, Nagaenko A V, Yurasov Y I, Verbenko I A, Parinov I A, Reznichenko L A
Research Institute of Physics, Southern Federal University, Rostov-on-Don, Russia.
National Kaohsiung University of Science and Technology, Department of Marine Environmental Engineering, Kaohsiung, Taiwan.
Heliyon. 2020 Oct 24;6(10):e05197. doi: 10.1016/j.heliyon.2020.e05197. eCollection 2020 Oct.
Ceramics of binary systems solid solutions (1 - )NaNbO - CaNbO and (1 - )NaNbO - SrNbO with non-isostructural extreme components were prepared by the solid-phase reactions technique with the following sintering using conventional ceramic technology. It was found that ceramics with ≤ 0.2 have a perovskite structure. Layered type of structure predominates in the concentration range 0.2 < ≤ 1. Phase diagrams of both systems at room temperature have been determined in the perovskite area. It was shown that this area contains two concentration regions with the different crystal structures and the morphotropic phase boundary between them. Microstructure and dielectric characteristics of selected solid solutions were investigated. The influence of technological regulations, such as mechanical activation and variation of sintering temperatures, on the formation of the microstructure and dielectric characteristics was studied for the individually selected concentrations ( = 0.1 and = 0.25). Dielectric characteristics of ceramics revealed the presence of the Maxwell-Wagner polarization and its corresponding relaxation in the solid solutions (1 - )NaNbO - CaNbO at x > 0.20.
采用传统陶瓷技术通过固相反应法制备了具有非等结构极端组分的二元体系固溶体（1 - ）NaNbO₃ - CaNbO₃和（1 - ）NaNbO₃ - SrNbO₃陶瓷，并进行了后续烧结。发现x≤0.2的陶瓷具有钙钛矿结构。在0.2＜x≤1的浓度范围内，层状结构占主导。已确定了两个体系在室温下钙钛矿区域的相图。结果表明，该区域包含两个具有不同晶体结构的浓度区域以及它们之间的同型相界。研究了所选固溶体的微观结构和介电特性。针对单独选定的浓度（x = 0.1和x = 0.25），研究了诸如机械活化和烧结温度变化等工艺规则对微观结构形成和介电特性的影响。陶瓷的介电特性表明，在x＞0.20的固溶体（1 - ）NaNbO₃ - CaNbO₃中存在麦克斯韦 - 瓦格纳极化及其相应的弛豫。
