Piezoelectric and electromechanical properties of ultrahigh temperature CaBi₂Nb₂O₉ ceramics

Abstract

Aurivillius-type bismuth layer-structured ferroelectrics (BLSFs) have received significant attention for their potential use in non-volatile ferroelectric random-access memory (NvRAMs) and high-temperature piezoelectric devices, owing to their fatigue-free properties and their relatively high Curie temperature T C , respectively [1-5]. However, the piezoelectric activities in pure and modified BLSFs were found to be very low [6][7][8][9][10].Recently, we successfully prepared A-site lithium and cerium cosubstituted and B-site cobalt modified Na 0.5 Bi 4.5 Ti 4 O 15 (NBT) piezoelectric ceramics, which show superior piezoelectric properties and excellent thermal stability [11,12]. The optimal NBT piezoelectric ceramics possess a high piezoelectric coefficient d 33 of 30 pC/N and high Curie temperature T C above 650 °C. However, the piezoelectric activities for BLSF materials with higher Curie temperature, being on the order of 900 °C, were found to be inferior to that of NBT ceramics, with piezoelectric coefficient d 33 values lower than 10 pC/N. Moreover, the ultrahigh temperature (T C > 900 °C) bismuth layer-structured compounds were very rare.Calcium bismuth niobate (CaBi 2 Nb 2 O 9 , CBN) [13][14][15][16][17], which is made up of (CaNb 2 O 7 ) 2between (Bi 2 O 2 ) 2+

Study on properties of tantalum-dopedLa2Ti2O7ferroelectric ceramics

“…5 So the general need for stable piezoelectric materials over a wide temperature range evokes an increasing interest to develop piezoceramics with high T c . Currently, dominating studies on high-temperature piezoelectric ceramics are focused on lead-free (K,Na)NbO 3 -based ceramics 6,7 and bismuth layer-structured ferroelectric ceramics, such as CaBi 2 3,8,9 However, the Curie points of these piezoelectric ceramics are limited to 950 C, limiting their practical applications at very high temperatures. The highest Curie temperatures have been found in some perovskite-like layer structured (PLS) ferroelectrics with a general formula of A 2 B 2 O 7 , such as La 2 Ti 2 O 7 (T c $ 1461 C), Nd 2 Ti 2 O 7 (T c $ 1482 C), Sr 2 Nb 2 O 7 (T c $ 1327 C), etc.…”

Grain oriented growth and properties of ultra-high temperature CaBi2Nb2O9 piezoelectric ceramics

“…When the maximum electric field intensity is E m = 100 kV/cm, the residual polarization (2 P r ) is 0.8 C/cm 2 and the coercive field (2 E r ) is 48.6 kV/cm for ceramics prepared by new technique. In contrast, its conventional counterpart exhibits ring-like curve, with larger loss [6,9]. For the ceramics prepared by the new technique, the compactness is enhanced with oriented grain growth, resulting in much easier domain reversion.…”

“…In particular, it plays important roles in technical fields such as information detection, conversion, processing and storage [1][2][3][4]. With the rapid development of modern science and technologies, many fields, such as atomic energy, power, aviation, metallurgy and petroleum, urgently require electronic devices that can operate under much higher temperatures [5,6]. However, it is rather difficult to develop ultra-high temperature piezoelectric properties.…”

“…However, their performances are limited by the spatially two-dimensional structure due to spontaneous polarization orientation, which brings them disadvantages such as high coercive field E c , difficult polarization and low piezoelectric activity [7][8][9][10]. Recently, many researches have been carried out on developing bismuth layer-structured piezoelectric ceramics by researchers all over the world [5][6][7][8][9][10][11][12][13][14][15]. Of those works, the most representative ones including Yan from Queen Mary University of London, Zhang from Pennsylvania State University, Tsuzuki from Waseda University and Damjanovic from EPFL Lab of Switzerland.…”

Study on the Textured CaBi4Ti4O15 Ceramics with Sc Modification

“…Thus CBT ceramics exhibit a piezoelectric property of only 3~7 pC/N [10]. To overcome these disadvantages, lots of research works about CBT ceramics was focused on enhancing its properties by rare-earth element doping and grain orientation techniques [11,12], etc.…”