Enhanced piezoelectric activity in high-temperature Bi_1−x−ySm_xLa_yFeO₃ lead-free ceramics

Abstract

We have developed a high-temperature bismuth ferrite ceramics with enhanced piezoelectric activity by chemical modifications, that is, the Bi 1ÀxÀy Sm x La y FeO 3 (0 r x r 0.30 and 0 r y r 0.15) lead-free ceramics were prepared by a conventional solid-state method. The influences of La and Sm content on their microstructure and electrical properties were systematically investigated. The ceramics with 0 r x o 0.10 (y = 0.05) or 0 r y r 0.15 (x = 0.025) belong to a triclinic phase, and a mixed structure with rhombohedral-like and orthorhombic phases was found in the ones with 0.10 r x r 0.30 (y = 0.05).The electrical properties of the ceramics can be operated by refining the x and y values. A very low dielectric loss (tan d B 0.43%) was shown in the ceramics with x = 0.025 and y = 0.05 because of the involvement of low defect concentrations. In addition, the ceramics with x = 0.025 and y = 0.05 also possess a high piezoelectric activity (d 33 B 50 pC N À1 ), which is larger with the respect to the previously reported results in high-temperature piezoceramics with a Curie temperature of 4600 1C, and a better thermal stability of piezoelectricity in 20-700 1C is also shown. We believe that this material system is suitable for high-temperature piezoelectric applications.

Temperature dependent piezoelectric response and strain–electric-field hysteresis of rare-earth modified bismuth ferrite ceramics

“…La and Sm) 27 . These high depolarization temperatures indicate a high T c , and hence potential for these materials for applications at elevated temperatures.…”

“…To date, preparing RE-BFO ceramics has proven to be arduous and the synthesis method has a significant impact on the chemical homogeneity, phase composition and functional behavior 18 . As a result, the reported electrical properties of RE-BFO ceramics vary widely 5,9,[18][19][20][21][22][23][24][25][26] , and a limited number of studies demonstrate either apparent saturated switching strains 9,18 , saturated polarizations 25,26 or high depoling temperatures [26][27][28] . Therefore, further investigation is still required in order to characterize and understand the electromechanical properties and high-temperature functionality of RE-BFO ceramics.…”

Chemical Synthesis and Structural Properties of Nd, Gd and Dy Doped BiFeO3 Lead Free Ceramics

“…Bi 1-x-y Sm x La y FeO 3 ), the ceramic with 0≤ x≤0.1 belongs to the triclinic structure, the ceramics with 0.1≤ x≤0.3 have a mixed phase (rhombohedral+orthorhombic) and a triclinic phase was observed for 0≤y≤0.15 ceramics. A low tanδ (∼ 0.43%) and a large d 33 (∼50 pC/N) were observed for x=0.025, y=0.05 ceramic so this is promising candidate for high temperature applications [6]. For Gd substituted Bi 1-x Gd x FeO 3 a compositional driven structural phase transition R3c → Pn2 1 a occur at x=0.1 and Pn2 1 a → Pnma occur in the range of 0.2<x<0.3 and was proved to be more effective in improving the multiferroic property of antiferromagnetic BiFeO 3 [7].…”

Study the influence of Nd and Co/Cr co-substitutions on structural, electrical and magnetic properties of BiFeO 3 nanoparticles

“…Bismuth ferrite (BFO) is the only single-phase multiferroic that exhibits ferroelectric (T C = 825 °C) and antiferromagnetic (T N = 370 °C) ordering simultaneously well above the room temperature [5,6]. Also, it possesses rhombohedrally distorted perovskite structure (ABO 3 type), in which A-site responsible for electric ordering and B-site for magnetism [7].…”