(K,Na)NbO₃-based lead-free ceramics with enhanced temperature-stable piezoelectricity and efficient red luminescence

Abstract

There has been a surge of research interest in the promising lead-free potassiumsodium niobate (KNN)-based ceramics, applications of which could be significantly promoted by improving thermal stability of piezoelectricity. Besides, endowing the KNN-based ceramics with photoluminescence property by rare-earth-ion doping can make them more completive lead-free counterparts in potential applications such as novel multifunctional sensing devices. Herein, a novel KNN-based ceramic material doped with Eu was elaborately designed to simultaneously obtain enhanced temperaturestable piezoelectricity and good luminescence property. By the introduction of diffused phase transition and the modulation of unit cell distortion, a large piezoelectric strain coefficient (d * 33 ) with a small variation (590±59 pm/V) over a wide temperature range (from room temperature to 110 ℃) was realized. The optimal composition also exhibited a considerable piezoelectric coefficient (d 33 ) with small fluctuation (330±33 pC/N) from 20 to 80 ℃. In addition to the enhanced temperature-stable piezoelectricity, the luminescence of these ceramics was slightly enhanced with the elevation of BaZrO 3 (BZ) doping contents, which could be attributed to the increased compositional disorder and the decreased unit cell distortion of the matrix material. Moreover, an optical characteristic was more prominent at ultra-low temperatures. This work unprecedentedly provides a novel paradigm for the design of multifunctional KNN-based ceramics with enhanced temperature-stable piezoelectricity and good luminescence property, revealing the great potential of the rare-earth-element-doped KNN material for future applications in the novel multifunctional devices.

Dy3+doped (K,Na)NbO3-based multifunctional ceramics for achieving enhanced temperature-stable piezoelectricity and non-contact optical temperature sensing performance

“…This phenomenon can be ascribed to the enhancement of domain wall mobility, which is associated with the more flat energy profile due to the decreased unit cell distortion. 12,20,22,37…”

“…This phenomenon can be ascribed to the enhancement of domain wall mobility, which is associated with the more flat energy profile due to the decreased unit cell distortion. 12,20,22,37 Fig. 4 depicts the variations of d 33 , planar electromechanical coupling coefficient k p , and mechanical quality factor Q m as the function of DyNZ concentration for LKNNS-BZ-xDyNZ ceramics at room temperature.…”

“…7,14,15,19 Following the guidance of this strategy, excellent large-signal piezoelectric deformation performance associated with remarkable thermal stability has been achieved in KNN-based ceramics. 7,[14][15][16][20][21][22][23] Compared with the large-signal piezoelectricity, the study on the temperature dependence of small signal d 33 is lacking. The small-signal d 33 plays an irreplaceable role in applications regarding vibration sensors or ultrasonic devices.…”

The Integration of Two-Dimensional Materials and Ferroelectrics for Device Applications

“…Von Neumann architecture created in the mid-1940s by John von Neumann has gained great success in the modern information society . However, the shared bus can result in limited throughput between the central processing unit (CPU) and memory, which is called the von Neumann bottleneck, affecting the efficiency and overall performance of the system. − Thus, many efforts have been devoted to the exploration of devices enabling computing paradigms such as in-memory computing and numerous computing to meet the growing demands of computing performance with high throughput and high energy efficiency. − Meanwhile, devices are moving toward the trend of high integration, light weight, multifunction, low voltage, and low energy cost. − Besides, the coming era of wearable and portable electronics has pushed the quest for devices with intriguing features such as mechanical flexibility, conformal characteristics, and self-powered capacity. ,,, Therefore, it is urgently desired to explore intriguing devices based on advanced materials or innovative architectures which go beyond the current Si-CMOS technologies. ,,− With fascinating nonvolatile features and low power consumption, the devices based on emerging 2D materials integrated with ferroelectrics enable innovative functions such as in-memory computing and ultralow-voltage operation, which is promising in addressing the above challenges.…”

Synthesis of CaNb2O6 with a Rynersonite-like Structure: Morphology, Rietveld Refinement, Optical, and Vibrational Properties

“…The study of niobium-based oxides, such as pyrochlores, perovskites, and columbites, has led to numerous applications in energy storage, , photocatalysis, , piezoelectricity, − optics, and magnetism . One important member of this family is Calcium Niobate – CaNb 2 O 6 .…”