Near-zero-temperature coefficient piezoelectric ceramic for surface acoustic waves and preparation method thereof

Abstract

The invention relates to a formula composition of near-zero-temperature coefficient piezoelectric ceramic for surface acoustic waves, which is prepared from common chemical raw materials by a conventional solid-phase process. The invention is characterized in that the formula of the piezoelectric ceramic is [(Pb(1-3 / 2x+y / 2)Lnx][Ti(0.98-y)Mn0.02By]O3, wherein 0.01<=x<=0.5; Ln is Ce, Sm or Gd; 0.01<=y<=0.8; and B is In or Yb. The delay time temperature coefficient (T[CD]) of the prepared piezoelectric ceramic is approximate to zero, the surface acoustic wave propagation velocity (Upsilon[s]) is 2500 m / s or so, and the dielectric constant is 230 or so. The mechanical factor of merit (Q[m]) is 2000 or so, the surface acoustic wave electromechanical coupling factor (K[s]) is 0.18 or so, and the Curie temperature is 350 DEG C or so.

Description

technical field [0001] The invention relates to the technical field of inorganic non-metallic materials, in particular to a composition of piezoelectric ceramics for near-zero temperature coefficient surface acoustic waves; it adopts a conventional solid-phase method for preparing ceramics, and uses common chemical raw materials to prepare near-zero temperature coefficient piezoelectric ceramics. The piezoelectric ceramics for surface acoustic wave with temperature coefficient is suitable for preparing surface acoustic wave devices. technical background [0002] Piezoelectric ceramics have excellent piezoelectric effects and are widely used in functional ceramics, such as sensors, transducers, filters, etc., and play an important role in the national economy and defense industry. Piezoelectric ceramics are mainly Lead zirconate titanate-based piezoelectric ceramics and their ternary and quaternary piezoelectric ceramics; at present, the production of surface acoustic w...

AI Technical Summary

Problems solved by technology

[0002] Piezoelectric ceramics have excellent piezoelectric effects and are widely used in functional ceramics, such as sensors, transducers, filters, etc., and play an important role in the national economy and defense industry. Piezoelectric ceramics are mainly Lead zirconate titanate-based piezoelectric ceramics and their ternary and quaternary piezoelectric ceramics; at present, the production of surface acoustic wave devices is mainly lead zirconate titanate-based piezoelectric ceramics and crystal materials, but crystal materials are difficult to meet high electromechanical coupling coefficient and low Temperature coefficient requirements, single crystal materials are generally expensive, and generally they are anisotropic materials, so high-precision directional cutting technology is required, which is also its shortcoming; lead zirconate titanate-based piezoelectric ceramics are only used in low-frequency surface acoustic waves There are application reports in the field of (SAW) devices, but its temperature coefficient is too large to be used in the production of high-frequency surface acoustic wave (SAW) devices; lead titanate ceramics have excellent piezoelectric properties, and through various substitution and doping methods , people have overcome the sintering difficulties, and have obtained some formulas that are widely used in different fields, especially in the high frequency field; through research, we have obtained lead titanate piezoelectric ceramics for near zero temperature coefficient high frequency surface acoustic wave (SAW)