Processing of 0.55(Ba_0.9Ca_0.1)TiO₃‐0.45Ba(Sn_0.2Ti_0.8)O₃ lead‐free ceramics with high piezoelectricity

Abstract

We report a large piezoelectric constant (d33), 720 pC/N and converse piezoelectric constant (d33*), 2215 pm/V for 0.55(Ba0.9Ca0.1)TiO3‐0.45Ba(Sn0.2Ti0.8)O3 ceramics; the biggest value achieved for lead‐free piezoceramics so far. The ceramic powders were calcined between 1050°C‐1350°C and sintered at 1480°C. The best properties were obtained at a calcination temperature (CT) of 1350°C. The fitting combination of processing and microstructural parameters for example, initial powder particle size >2 µm, ceramics density ~95%, and grain size ~40 µm led to a formation of orthorhombic‐tetragonal‐pseudo‐cubic (O‐T‐PC) mixed phase boundary near room temperature, supported by Raman spectra, pointed to the extremely high piezoelectric activity. These conditions significantly increase piezoelectric constants, together with high relative permittivity (εr) >5000 and a low loss tangent (tan δ) of 0.029. In addition, the d33 value stabilizes in the range of 400‐500 pC/N for all samples calcined between 1050°C and 1250°C. The results entail that the (Ba,Ca)(Sn,Ti)O3 ceramics are strong contenders to be a substitute for lead‐based materials for room temperature applications.

Comparative Study of PVDF Sheets and Their Sensitivity to Mechanical Vibrations: The Role of Dimensions, Molecular Weight, Stretching and Poling

“…Vibration sensing capabilities were investigated by measuring the charge piezoelectric coefficient d 33 on the electrometer 6517b (Keithley, Solon, OH, USA) as has been similarly published in preceding studies [ 29 , 30 , 31 , 32 ]. The mechanical force oscillations were induced by a vibration test system TV 50018 (Tira, Schalkau, Germany) and detected by a sensor 208C01 (PCB Piezotronics, Hückelhoven, Germany).…”

Enhanced Piezoelectric, Ferroelectric, and Electrostrictive Properties of Lead‐Free (1‐x)BCZT‐(x)BCST Electroceramics with Energy Harvesting Capability

“…[1][2][3][4][5][6][7] It is well known that lead (Pb) based materials, such as Pb(Zr,Ti)O 3 (PZT) and Pb(Mg 1/3 Nb 2/3 )-PbTiO 3 (PMN-PT), are the most commonly utilized piezoelectric materials with excellent piezoelectric properties (piezoelectric coefficient d 33 ≈580 pC N −1 ), presence of morphotropic phase boundary, and higher working temperatures. [2][3][4][5][6][7][8][9][10][11][12] However, these harmful Pb-based piezoelectric ceramics, which contain ≈60 wt% of Pb and are toxic, contribute to environmental contamination and pose a risk to human health. In this connection, European Union legislation (RoHS; Directive 2002/95/EC & Directive 2011/65/EU) [13] placed limitations/restrictions on the use of Pb-based materials which stimulates the scientific and engineering community to search for high-performance, eco-friendly, and Pb-free piezoelectric materials.…”

“…In this connection, European Union legislation (RoHS; Directive 2002/95/EC & Directive 2011/65/EU) [13] placed limitations/restrictions on the use of Pb-based materials which stimulates the scientific and engineering community to search for high-performance, eco-friendly, and Pb-free piezoelectric materials. [2][3][4][5][6][7][8][9][10][11][12] The restrictions have forced the replacement of Pb-use in a number of technological applications. Unfortunately, the suitable Pb-free substitutes are still not readily available at this time.…”

“…Furthermore, the threat of removing the current exemptions, combined with the growing awareness of environmental and health issues related to these emissions, has further ignited this scientific interest in developing novel and effective Pb-free alternatives for utilization in a number of technologies. [11,12,14] In fact, in recent years, the scientific and engineering community directed significant efforts to develop alternate material systems to circumvent the use of Pb and to minimize the use of Pb-based piezoelectric materials in various technologies so that the environment can be protected along with the human health. [10][11][12]14] The design and development activities of Pb-free materials resulted in few alternate materials in recent years.…”

“…[11,12,14] In fact, in recent years, the scientific and engineering community directed significant efforts to develop alternate material systems to circumvent the use of Pb and to minimize the use of Pb-based piezoelectric materials in various technologies so that the environment can be protected along with the human health. [10][11][12]14] The design and development activities of Pb-free materials resulted in few alternate materials in recent years. Some of the alternate and Pb-free materials include BaTiO 3 (BT), (K 0.5 Na 0.5 )NbO 3 (KNN), (Bi 0.5 ,Ni 0.5 )TiO 3 (BNT), and (Bi 0.5 ,K 0.5 )TiO 3 (BKT), which are among the best prospects to replace Pb-based materials.…”