Piezoceramic material for high-temperature piezoelectric sensors and preparation method of piezoceramic material

Abstract

The invention provides a piezoceramic material for high-temperature piezoelectric sensors and a preparation method of the piezoceramic material. A chemical composition of the ceramic material is Ca1-x-y-z(LM)x / 2Ny(NaBi)z / 2Bi2Ta2O9, wherein L refers to Li, Na and K; M refers to a lanthanide metal element or Bi; N refers to Sr or bivalent vacancy; x+y+z is larger than or equal to 0 and smaller thanor equal to 1, x is larger than or equal to 0 and smaller than or equal to 0.4, y is larger than or equal to 0 and smaller than or equal to 0.1, and z is larger than or equal to 0 and smaller than orequal to 1; when z is not equal to 0, (LM) cannot be (NaBi). The piezoceramic material has advantages of high Curie temperature, high high-temperature direct-current electrical resistivity, high piezoelectric activity and high thermal stability.

Description

technical field [0001] The invention relates to the field of material technology, in particular to a piezoelectric ceramic material used for a high-temperature piezoelectric sensor and a preparation method thereof. Background technique [0002] Piezoelectric ceramics are an important new functional material that can realize mutual conversion between mechanical energy and electrical energy, and have been widely used in many fields such as aerospace, automobiles, communications, and consumer electronics. Lead-based piezoelectric ceramics represented by lead zirconate titanate (PZT) are the most widely used piezoelectric ceramic materials due to their excellent piezoelectric and dielectric properties. With the development and progress of science and technology, some high-tech fields, such as aerospace, navigation, nuclear energy, geological exploration, etc., have put forward urgent and demanding application requirements for piezoelectric ceramics, requiring piezoelectric ceram...

AI Technical Summary

Problems solved by technology

Although bismuth layered ferroelectrics have a high Curie temperature, their piezoelectricity is poor due to their special crystal structure that confines their spontaneous polarization to a two-dimensional plane.

Although people can effectively enhance its piezoelectric activity through ion doping or preparation process improvement, with the introduction of doping ions, the Curie temperature usually decreases significantly, and the high-temperature resistivity ρ (@650 ℃) Usually less than 10 5 The magnitude of Ω·cm will seriously affect the temperature stability of high-temperature piezoelectric sensors

[0004] Ca Bi 2 Ta 2 o 9 (CBTa) is a typical bismuth-containing layered piezoelectric material, which consists of a perovskite-like layer (CaTa 2 o 7 ) 2- and (Bi 2 o 2 ) 2+ Layers are regularly arranged alternately, and the Curie temperature is as high as 940 ℃, but its piezoelectricity is still very low, and the piezoelectric constant d 33 Only 4 pC / N, with a resistivity of ~10 at 650 °C 5 Ω·cm, and the piezoelectric constant d 33 The attenuation is obvious with the increase of temperature, which is not conducive to the improvement of the stability of high-temperature piezoelectric sensors

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