Effects of Li content on the phase structure and electrical properties of lead-free (K0.46−x∕2Na0.54−x∕2Lix)(Nb0.76Ta0.20Sb0.04)O3 ceramics

Abstract

Multiferroic response of nanocrystalline lithium niobate J. Appl. Phys. 111, 07D907 (2012) Non-radiative complete surface acoustic wave bandgap for finite-depth holey phononic crystal in lithium niobate Lead-free ͑K 0.46−x/2 Na 0.54−x/2 Li x ͒͑Nb 0.76 Ta 0.20 Sb 0.04 ͒O 3 piezoelectric ceramics were prepared by the conventional solid state sintering method without cold-isostatic pressing process. The x-ray diffraction and Raman scattering results show that the phase structure of the ceramics undergoes a transition from pseudocubic to tetragonal phase with increasing x from 0 to 0.10. Significantly

Effect of Li on the microstructure and electrical properties of (K0.17Na0.83)NbO3 lead-free piezoceramics

“…3 shows the temperature dependence of the relative permittivity measured at 10 kHz. As reported by Guo and Chang et al [3,14], the phase transition temperatures T C and T O-T shifts upward and downward respectively with the increasing of Li content. Moreover, the relations between T C , x and T O-T , x obey Vegard's law as shown in Fig.…”

Phase transition-induced high electromechanical activity in [(K0.5Na0.5)1−xLix](Nb0.8Ta0.2)O3 lead-free ceramic system

“…Accordingly, the development of environmentally friendly lead-free ceramic systems has been an urgent demand in the recent decade. Among all the possible lead-free systems, the (K 0.5 Na 0.5 )NbO 3 (KNN)-based systems have received the most positive attention because their electromechanical properties can be greatly enhanced using Li and Ta in substitution for K (Na) and Nb, respectively [3][4][5][6][7][8][9]. The more general system (K,Na,Li)(Nb,Ta,Sb)O 3 , which not only can be synthesized by the conventional pressureless solid-state sintering method [6][7][8][9], but also possesses high piezoelectric d 33 values of >300 pC/N in polycrystalline ceramics and >400 pC/N in textured ceramics [10], has been widely accepted as a practicable lead-free replacement for the lead-based systems.…”

(K,Na)NbO3-based Lead-free Piezoelectric Materials: An Encounter with Scanning Probe Microscopy

“…So what really happens to the structure of KNN-based ceramics is not clear enough. Furthermore, the enhanced piezoelectric properties in the modified KNN were firstly attributed to the formation of the MPB similar to that observed in the PZT system [5,11,36,45], which was later on pointed out to be a different effect namely polymorphic phase transition (PPT) [15,22]. In any case, phase structure investigations in KNN-based ceramics are of paramount importance for obtaining excellent properties.…”