Ferroelectric Materials for High Temperature Piezoelectric Applications

Abstract

Electronic control and operation in almost all advanced devices or machines involve use of various sensors and actuators, many of which are based on piezoelectric (PE) effect. Ferroelectric (FE) materials forming a sub-group of piezoelectric materials have additional applications. Subject to success in materials and related developments, PE and FE devices perform competitively with alternative devices but at lower cost in most cases. There is increasing commercial and technical interest for PE actuators (ranging from electronic muscles, fuel injectors and inkjet printers to various vibrators), PE sensors (pressure and other sensors and motion detection to energy recovery), and ultrasonic imaging devices. PE to non-PE transition temperature (Curie temperature for FE PE materials) and piezoelectric coefficients together decide the choice of the right material for any particular application. Since most of these applications, including medical ultrasonic imaging, are done at or near room temperature, low Curie temperature (but otherwise attractive) piezoelectric materials, based on barium titanate (BT), lead zirconate titanate (PZT) and relaxor ferroelectric ceramics, have served us well. However, a few important applications, in automobile and rocket exhausts, in some engines and gadgets, and inside high pressure molten metal in nuclear Fast Breeder Reactors (FBRs) involve high temperatures (HTs), higher than or nearing the Curie temperature of even PZT. These applications including FBRs, generating nuclear fuel and power, demand development of high temperature piezoelectric materials. FBRs can close the nuclear fuel cycle by partially using the nuclear waste (containing U-238) and thus minimize waste disposal problem. That makes nuclear energy a better green energy. Working on Th-232 from monazite sand, FBRs can breed Th-233, a nuclear fuel, with simultaneous generation of electricity. Ranging and imaging of nuclear fuel rods and control rods through the liquid metal coolant in FBRs, especially during insertion and withdrawal, help correct positioning of the rods to avoid any misalignment and possible nuclear accident. This “viewing” through the optically opaque liquid metal or alloy coolant, is possible by ultrasonic imaging of the rods using HT PE ultrasonic-generators and-detectors, an active area of research. Lithium niobate with T(Curie) > 1000°C and orthorhombic PbNb2O6with T(Curie) > 570°C are two of many HT PE materials under development or in trial runs. In the present work, world-wide R & D on HT piezoelectric materials has been reviewed after an outline of the basics.

Polymer Composites for Flexible Electromagnetic Shields

“…These are piezoelectric. Our o‐PN has shown a high Curie Temperature of 570 °C, while Curie Temperature of BT has been measured to be 124 °C.…”

“…Barium titanate, BaTiO 3 , samples have been prepared from BaCO 3 (99.99%, white) and TiO 2 (99.99% GR, white) powders using solid state reaction, by few firings at ≈1300 °C for a total time of 12 h. Pellets of o‐PN (orthorhombic PbNb 2 O 6 ) have been prepared from PbO (99.999% pure PbO, from Aldrich) and Nb 2 O 5 (99.9% pure, from Loba Chemie Pvt. Ltd.) powders by heating in three stages, and quenching after the last firing (at 1270 °C) stage.…”

“…XRD confirmed each sample to a single phase sample. XRD, TEM, and DSC characterizations have been carried out for CdO, BT, and PN samples before powdering for composite formation with the polymeric binder.…”

Ferroelectric Domain Structure and Local Piezoelectric Properties of Lead-Free (Ka0.5Na0.5)NbO3 and BiFeO3-Based Piezoelectric Ceramics

“…Stabilization of the ceramics in a wide temperature range and improvement of the properties at close to room temperature is very important for various applications [103]. Pure BFO ceramics demonstrate a significant increase of the piezoelectric and dielectric properties at elevated temperatures [104].…”

The nitride ceramics surface layer stress state transformation under the variation of the TiC-coating thickness. The applied load is the heat current

“…Т ехнический прогресс в сфере изделий для высокотемпературного применения во многом зависит от успехов в создании новых керамических материалов многофункционального назначения [1][2][3]. Комплекс свойств керамики на основе нитрида кремния обеспечивает ее эффективное применение в горячих зонах двигателей и энергоустановок, а также соплах, горелках и инструментах [4][5][6].…”