The pyrochlore phase in ferroelectric and piezoelectric materials is the main obstacle device application due to its poor electrical properties. Especially, the pyrochlore phase is frequently observed in the perovskite-based metal-oxide materials including piezoelectric and ferroelectric ceramics, which are based on solid-state reaction methods for fabrication. To overcome these problems, advanced innovative methods such as partial oxalate process will be investigated. In this method, crystalized magnesium niobite (MN) and lead titanate (PT) powders will be coated with a certain amount of lead oxalate and, then, the calcination process can be carried out to form the PMN-PT without pyrochlore phase. In this study, (1−x)PMN-xPT ceramics near the morphotropic phase boundary (MPB), with compositions of x = 0.25⁻0.40, have been prepared employing the partial oxalate method at various temperatures. The crystalline, microstructure, and piezoelectric properties of (1−x)PMN-xPT ceramics depending on the sintering temperature were intensively investigated and discussed. By optimizing the sintering temperature and compositions from the PMN-PT ceramics, the maximum value of the piezoelectric charge coefficient (d33) of 665pC/N, planar electromechanical coupling factor (kp) of 77.8%, dielectric constant (εr) of 3230, and remanent polarization (Pr) of 31.67 μC/cm2 were obtained.
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机译:铁电和压电材料中的Pyrochlore相是由于其差的电气性能差的主要障碍装置应用。特别地,在基于钙钛矿的金属氧化物材料中经常观察到吡螺旋阶段,包括压电和铁电陶瓷,其基于用于制造的固态反应方法。为了克服这些问题,将研究进一步的创新方法,如部分草酸过程。在该方法中,将结晶的铌铁矿石(Mn)和铅钛酸铅(Pt)粉末涂有一定量的草酸铅,然后,可以进行煅烧过程以形成没有烧谱相的PMN-PT。在本研究中,已经制备在不同温度下采用X =0.250.40的组合物的Morphotopic相位边界(MPB)附近的PMN-XPT陶瓷。根据烧结温度的(1-X)PMN-XPT陶瓷的结晶,微观结构和压电性能被强烈地研究和讨论。通过优化来自PMN-PT陶瓷的烧结温度和组合物,压电电荷系数(D33)的最大值为665pc / n,平面机电耦合因子(kp)为77.8%,介电常数(εr),3230,获得了31.67μC/ cm 2的剩余偏振(PR)。
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