Preparation of barium titanate-bismuth magnesium titanate ceramics with high Curie temperature and their piezoelectric properties

Abstract

Barium titanate (BaTiO 3 , BT)bismuth magnesium titanium oxide (Bi(Mg 0.5 Ti 0.5 )O 3 , BMT) solid solution system ceramics were prepared using nanoparticles in atmosphere to enhance Curie temperature (Tc) of BT, 132°C, to much higher temperature. Optimization of calcination and sintering conditions resulted in a formation of a perovskite single-phase, and their densities were always greater than 94%. The synchrotron XRD measurement revealed that the all ions in the ceramics had almost homogeneous distribution. Temperature dependence of dielectric property revealed that the BTBMT system ceramics was typical relaxor materials, and for the 0.5BT0.5BMT ceramics, the dielectric maximum was clearly observed at 360°C. Finally, their apparent piezoelectric constant (d*) were measured by electric-field dependence of strain at room temperature, and the d* value was measured at around 60 pm/V for the 0.4BT0.6BMT ceramics.

Low sintering temperature and high piezoelectric properties of Li-doped (Ba,Ca)(Ti,Zr)O3 lead-free ceramics

“…However, the environmental concerns urgently require lead-free ceramics to substitute for the PZT with high content of toxic lead [1,2]. BaTiO 3 (BT) is one of the good candidates for lead-free ceramics due to its promising piezoelectric properties and solid solution with other perovskites, such as BT-KNbO 3 [3], BT-Bi(Mg 1/2 Ti 1/2 )O 3 [4], BT-Bi 0.5 Na 0.5 TiO 3 -Bi 0.5 K 0.5 TiO 3 [5], BT-Bi(Zn 1/2 Ti 1/2 )O 3 -BiFeO 3 [6], BT-Bi 0.5 Na 0.5 TiO 3 -KNbO 3 [7], Bi 0.5 Na 0.5 TiO 3 -(Ba,Ca)(Ti,Zr)O 3 [8], (Ba,Ca)(Ti,Sn)O 3 -(Ba,Ca)(Ti,Zr)O 3 [9], BT-CaTiO 3 -BaHfO 3 [10]. Among them, the BaTi 0.8 Zr 0.2 O 3 -(Ba 0.7 Ca 0.3 )TiO 3 (BCTZ) composition lead-free ceramics, which were reported by Liu and Ren [11], have been attracted great attention because of their high piezoelectricity arising from the polymorphic phase transition (PPT) at room temperature.…”

Temperature-stable dielectric properties from −20°C to 430°C in the system BaTiO3–Bi(Mg0.5Zr0.5)O3

“…An alternative and low-cost system, (1-x)Ba 0.8 Ca 0.2 TiO 3 -xBi(Mg 0.5 Ti 0.5 )O 3 has r = 830 ± 10 % and low, tan ≤ 0.02, from ~50ºC to 550 ºC for composition x = 0.5; r = 950 ± 10 % over the wide temperature range from +80 °C to 600 °C for composition x = 0.45 [6,12,28]. The end member Bi(Mg 0.5 Ti 0.5 )O 3 is of rhombohedral structure at room temperature, with T c ~ 430 ºC but can only be prepared at high pressure (6 GPa) at a temperature ~1000 ºC [20,21]. However, it forms useful solid solutions under normal processing conditions with a number of other perovskites [6,[20][21][22].…”

“…The end member Bi(Mg 0.5 Ti 0.5 )O 3 is of rhombohedral structure at room temperature, with T c ~ 430 ºC but can only be prepared at high pressure (6 GPa) at a temperature ~1000 ºC [20,21]. However, it forms useful solid solutions under normal processing conditions with a number of other perovskites [6,[20][21][22]. The system Bi(Mg 0.5 Ti 0.5 )O 3 -BaTiO 3 (BMT-BT) [20] exhibits a near temperature stable r response ( r~ 2400 ±15%) across the temperature range 167-400 ºC for composition 50 BMT-50 BT.…”

Temperature‐Stable Relative Permittivity from −70°C to 500°C in (Ba0.8Ca0.2)TiO3–Bi(Mg0.5Ti0.5)O3–NaNbO3 Ceramics

“…Although this material has excellent temperature stability at elevated temperatures, the ~10 wt% Sc 2 O 3 content leads to high material costs. There are also reports of temperature stability in BaTiO 3 –Bi(Mg 1/2 Ti 1/2 )O 3 solid solutions …”