Domain size engineering in 0.5%MnO2-(K0.5Na0.5)NbO3 lead free piezoelectric crystals

Abstract

The piezoelectric property of [001]-oriented 0.5%MnO2-(K0.5Na0.5)NbO3 (Mn-KNN) crystals was studied as a function of domain size, being poled with different electric fields at 205 C (above orthorhombic to tetragonal phase transition temperature To-t). The piezoelectric coefficients d33 and relative dielectric constants er were found to increase from 270 pC/N to 350 pC/N and 730 to 850 with the domain size decreasing from 9 to 2 lm, respectively. The thermal stability of piezoelectric property was investigated, where the d33 value for [001]-oriented Mn-KNN crystals with domain size of 2 lm was found to decrease to 330 pC/N at depoling temperature of 150 C, with minimal variation of 6%. The results reveal that domain size engineering is an effective way to improve the piezoelectric properties of Mn-KNN crystals. Publication DetailsLin, D., Zhang, S., Cai, C. & Liu, W. (2015). Domain size engineering in 0.5%MnO2-(K0.5Na0.5)NbO3 lead free piezoelectric crystals. Journal Of Applied Physics, 117 (7) The piezoelectric property of [001]-oriented 0.5%MnO 2 -(K 0.5 Na 0.5 )NbO 3 (Mn-KNN) crystals was studied as a function of domain size, being poled with different electric fields at 205 C (above orthorhombic to tetragonal phase transition temperature T o-t ). The piezoelectric coefficients d 33 and relative dielectric constants e r were found to increase from 270 pC/N to 350 pC/N and 730 to 850 with the domain size decreasing from 9 to 2 lm, respectively. The thermal stability of piezoelectric property was investigated, where the d 33 value for [001]-oriented Mn-KNN crystals with domain size of 2 lm was found to decrease to 330 pC/N at depoling temperature of 150 C, with minimal variation of $6%. The results reveal that domain size engineering is an effective way to improve the piezoelectric properties of Mn-KNN crystals. V C 2015 AIP Publishing LLC.

High-Performance 0-3 Type Niobate-Based Lead-Free Piezoelectric Composite Ceramics with ZnO Inclusions

“…2,4 Significant efforts have been dedicated to addressing this issue; for example, attempts were made to lower the O-T phase transition temperature (T O-T ) to below room temperature and to synthesize highly textured KNN-based ceramics or single crystals. 2,7,[12][13][14][15][16] Unfortunately, the former failed to have good piezoelectricity (e.g., d 33 <300 pC/N) and the latter is too expensive for industrial applications. 7,12,13,15,16 Recently, composite designs of lead-free ceramics were proposed with both greater temperature stability and enhanced electrical properties.…”

“…2,7,[12][13][14][15][16] Unfortunately, the former failed to have good piezoelectricity (e.g., d 33 <300 pC/N) and the latter is too expensive for industrial applications. 7,12,13,15,16 Recently, composite designs of lead-free ceramics were proposed with both greater temperature stability and enhanced electrical properties. [17][18][19][20][21] For example, ferroelectric/relaxor composite ceramics consisting of a nonergodic relaxor (0.93BNT-0.07BT) and an ergodic relaxor (0.92BNT-0.06BT-0.02KNN) showed a low critical electric field required for inducing giant strain and a considerably low strain hysteresis, which was interpreted with a model based on two serially-connected capacitors.…”

Further Enhancing Piezoelectric Properties by Adding MnO2 in AgSbO3‐Modified (Li,K,Na)(Nb,Ta)O3 Lead‐Free Piezoceramics

“…It has been reported that MnO 2 addition could endow single crystals of KNN systems with a better piezoelectric response by modifying domain structure or lattice defects. [27][28][29] Besides, MnO 2 is deemed as one of the most intriguing additives in KNN-based ceramics because both "softening" or "hardening" characteristics of MnO 2 are simultaneously observed, which conduce to the increases in piezoelectric constant d 33 , relative permittivity e r , planar electromechanical coupling factor k p , and mechanical quality factor Q m , as well as the decrease in loss tangent tan d. [22][23][24][25][30][31][32] It has been found that a gentle decrease in T O-T and piezoelectric property enhancement could be achieved by the addition of AgSbO 3 . 33 As reported in previous work, 16,19 promising piezoelectric properties were achieved by the precise control of PPT point around room temperature in the AgSbO 3 -modified (Li, K, Na)(Nb,Ta)O 3 ceramics.…”

Phase transition and domain configuration of poled rhombohedral PIN–PZ–PMN–PT single crystals

“…Unfortunately, this phenomenon could not be exactly surveyed using PLM owing to the misalignment between domain walls and light beam. 36 However, from the viewpoint of free energy, we can interpret this result by studying the temperature-dependent piezoelectric property, as will be discussed later. When the temperature was prior to T C (183 o C), a total optical extinction spread over the crystal, indicating the formation of the paraelectric phase, as shown in Fig.…”

“…Previous reports suggest that the thickness of small domain size would increase the domain wall energy density. 36,40,41 In other words, according to free energy, the domain state will be unstable in the scope of phase transition, which immensely enhances the extrinsic contributions to the piezoelectric response, leading to the high piezoelectric coefficient around T R-T . From this point of view, the 33 * should be higher than that in T phase, which is consistent with the result shown in Fig.…”