Simultaneous realization of high transparency and piezoelectricity in low symmetry KNN‐based ceramics

Abstract

Transparent piezoelectric ceramic, as a lead‐free multifunctional ceramic, is in dire need of development for future high‐tech industries. However, excellent piezoelectricity and high transmittance are usually hard to achieve simultaneously, mainly due to the two mutual restricting factors (phase structure and grain size). In this work, we report that high piezoelectricity and transmittance can be obtained simultaneously in K0.5Na0.5NbO3 ceramics via Sr(Sc0.5Nb0.5)O3 (SSN) modification. The superior piezoelectric performance comes from the retain of orthorhombic phase structure at room temperature (RT); while the high transparency (>70% at 780 nm) can be attributed to the improved relative density and reduced grain size via SSN modification. Remarkably, in the sample with 0.05SSN modification, we realized a comprehensively high transmittance (73% at 780 nm) accompanied by a superior piezoelectric constant (d33 = 101 pC/N), which outperform other reported KNN‐based transparent ceramics to our best knowledge. Our results may provide insight for further developing the transparent piezoelectric ceramics by controlling the grain size and phase structure.

Highly Transparent Eu-Doped 0.72PMN-0.28PT Ceramics with Excellent Piezoelectricity

“…A comparison of the optical transmittance in the NIR region together with the piezoelectric coefficient d 33 between the studied 2.5Eu-PMN-28PT ceramic and other transparent piezoelectric ceramics is shown in Figure (the sample thickness of each material and the corresponding wavelength for the transmittance values in Figure are provided in Table S1 in the Supporting Information). The triangles in the diagram represent lead-free transparent piezoelectric ceramics, − most of which possess relatively high optical transmittance but very low d 33 . The rhombuses represent the lead-based transparent piezoelectric ceramics, ,,− which generally exhibit high piezoelectric coefficients but slightly low optical transmittance.…”

Thermally stable high strain and piezoelectric characteristics of (Li, Na, K)(Nb, Sb)O3‐CaZrO3 ceramics for piezo actuators

“…The d 33 value is calculated using the following equation: d 33 = 2 × Q 11 × ε T 33 × P r , where P r is the remnant polarization and Q 11 is the electrostriction coefficient. In general, as Q 11 is constant, the d 33 value is proportional to ε T 33 × P r . Moreover, k p is proportional to d 33 × g 33 , where g 33 is a piezoelectric voltage constant.…”

“…In general, as Q 11 is constant, the d 33 value is proportional to ε T 33 × P r . [26][27][28][29][30][31][32][33] Moreover, k p is proportional to d 33 × g 33 , where g 33 is a piezoelectric voltage constant. Therefore, a specimen with large P r and ε T 33 values could exhibit large d 33 and k p values.…”

Second‐order‐transition like characteristic contributes to strain temperature stability in (K, Na)NbO3‐based materials

“…Piezoelectric materials are indispensable components in our industrial production . Due to Pb toxicity in commercial lead‐based piezo‐materials, lead‐free piezoelectrics have received much attention in recent years . Potassium‐sodium niobate [(K, Na)NbO 3 , KNN] is one of the most promising lead‐free candidates because of its high Curie temperature ( T C =415 °C) and relatively good piezoelectric constant ( d 33 ) .…”

“…[1][2][3][4][5] Due to Pb toxicity in commercial leadbased piezo-materials, lead-free piezoelectrics have received much attention in recent years. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Potassium-sodium niobate [(K, Na)NbO 3 , KNN] is one of the most promising lead-free candidates because of its high Curie temperature (T C =415 °C) and relatively good piezoelectric constant (d 33 ). 8,[25][26][27][28] For small signal applications, such as sensors and microphones, d 33 is a research emphasis.…”