Bismuth ferrite-barium titanate based high-temperature lead-free piezoelectric ceramic with low dielectric loss and high-temperature stability and preparation method thereof

Abstract

The invention discloses bismuth ferrite-barium titanate based high-temperature lead-free piezoelectric ceramic with low dielectric loss and high-temperature stability and a preparation method thereof. The bismuth ferrite-barium titanate based high-temperature lead-free piezoelectric ceramic has a formulation composition with a general formula of (Bi<1-w>Mw)(Fe<1-t>Me'''t)O<3-x>BaTiO<3+y>Bi(Me'0.5Me''0.5)O<3+z>Bi(Zn0.5Ti0.5)O<3+u>NdCoO<3+m>P<+n>MnCO3, where x, y, z, u, m, n, t and w represent mol fractions; x is more than 0 and no more than 0.4; y is no less than 0 and no more than 0.1; z is more than 0 and less than 0.05; u is no less than 0 and no more than 0.1; m is more than 0 and no more than 0.1; n is more than 0 and no more than 0.1; w is no less than 0 and no more than 0.1; and t is no less than 0 and no more than 0.1. In the general formula, M and Me''' are trivalent metal elements; Me'' and M' respectively are a divalent metal element and a pentavalent metal element; and P is a sintering auxiliary agent. The piezoelectric ceramic provided by the invention has low dielectric loss and high-temperature stability and can be applied to the field of high temperature.

Description

technical field [0001] The invention relates to a high-temperature lead-free piezoelectric ceramic and a preparation method thereof, in particular to a bismuth ferrite-barium titanate-based high-temperature lead-free piezoelectric ceramic with low dielectric loss and high-temperature stability and a preparation method thereof. Background technique [0002] High-temperature piezoelectric ceramics are widely used in piezoelectric vibration sensors in aerospace, nuclear energy, oil exploration and other fields. BiFeO 3 -BaTiO 3 Piezoelectric ceramics have attracted great attention due to their lead-free, low sintering temperature, high Curie temperature, high depolarization temperature and good piezoelectric performance. However, due to the high dielectric loss of this system, it has not been able to be applied in practice. Therefore, how to reduce the dielectric loss of this system is the key technology for this system to be applied in high temperature fields. [0003] BF-B...

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Problems solved by technology

The generation of a large number of oxygen vacancies eventually makes the leakage conduction current of the sample high, resulting in difficult polarization

[0006] Literature [Serhiy O, J Am Ceram Soc,2009,92(12):2957-2961] reported BiFeO with high Curie temperature and good piezoelectric properties 3 – BaTiO 3 Lead-free piezoelectric ceramics, but need to be sintered in pure oxygen atmosphere, not suitable for industrial production, and its piezoelectric constant is low, only 116pC / N; literature [Ichiro Fujii, J Appl Phys,2011,50:09ND07] reported a Mn-doped BaTiO 3 -Bi(Mg 1 / 2 Ti 1 / 2 )O 3 -BiFeO 3 Lead-free piezoelectric ceramics, but the Curie temperature of the place with the best piezoelectric performance is only 470°C, and the best piezoelectric constant d 33 Only 94pC / N, no report on depolarization temperature and temperature stability; literature [Dae Su Kim, Appl.Phys.Lett.109, 202902 (2016)] reported that the piezoelectric performance increased from 70pC / N to N has been increased to 140pC / N, which can greatly improve the piezoelectric performance, but the dielectric loss and temperature stability have not been reported; the literature [Yongquan Guo, J Mater Sci: Mater Electron, 2017,28:5531–5547] reported that NdCoO 3 doped modified BFBT piezoelectric ceramics, and obtained d 33 = About 110pC / N, a piezoelectric ceramic with a Curie temperature of 605°C and a depolarization temperature of 525°C, but when the depolarization point is 525°C, its piezoelectric performance is only 80pC / N, and its dielectric loss is relatively high. Losses as high as 7%+ at best performing composition points

[0007] According to previous studies, the dielectric loss of the BF-BT system has not been effectively solved. Therefore, the key to the application of this system in the field of high-temperature piezoelectricity is how to control the dielectric loss of the system and make a breakthrough in this research. Bottleneck, it will be of great significance to the research progress of high temperature piezoelectric materials

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