Temperature‐Insensitive High Strain in Lead‐Free Bi0.5(Na0.84K0.16)0.5TiO3–0.04SrTiO3 Ceramics for Actuator Applications

• DOI: 10.1111/jace.13722
• Publication Date: 2015-08-26T11:31:50Z
• Authors: Rizwan Ahmed Malik; Ali Hussain; Adnan Maqbool; Arif Zaman; Chang‐Won Ahn; Jamil Ur Rahman; Tae‐Kwon Song; Won‐Jeong Kim; Myong‐Ho Kim
• Keywords: Tetragonal crystal system; Lattice constant

Lead‐free piezoelectric ceramics, 0.96[{Bi 0.5 (Na 0.84 K 0.16 ) } 1− x Li (Ti y Nb )O 3 ]–0.04SrTiO (BNKLiTN–ST) with , = 0–0.030, were synthesized by solid‐state reaction method. X‐ray diffraction patterns indicated that and successfully diffused into the BNKT – ST lattice formed a pure perovskite structure x, ≤ 0.025. Increasing contents ( 0.020) induced phase transformation from coexistent rhombohedral–tetragonal phases for ceramics to pseudocubic phase, resulting in degradation of remnant polarization coercive field. However, field‐induced strain was markedly enhanced at 0.020, giving rise giant dynamic constant d 33 * S max / E 800 pm/V). Furthermore, temperature dependence response showed temperature‐insensitivity up 120°C. To explore its potential device applications, 10‐layered stack‐type multilayer actuator fabricated optimal composition 0.020). This large 600 pm/V relatively low driving field 4.5 kV/mm suggesting highly promising results lead‐free BNT ‐based ceramics.