Lead-free piezoelectric film material and preparation method thereof

Abstract

The invention discloses a lead-free piezoelectric film material, which is a ferrocolumbium barium titanate calcium strontium film material with the ingredient and chemical formula of (Ba0.9CaxSr0.1-x)(Ti0.87Nbyfe0.13-y)O3, wherein x in the formula is more than 0 and is less than 0.1, and y is more than 0 and is less than 0.13. The material is obtained by that sol is prepared with an improved sol-gel method, and the sol is subjected to film formation by the spin-coating technology and is annealed. The piezoelectric coefficient d33 of the material is 320pC / N. In addition, the lead-free piezoelectric film material has the advantages of low leakage current, dense surface, even grain size, strong electric hysteresis effect and the like and is free from the microcrack. The lead-free piezoelectric film material has an important meaning for applying the ferroelectric film in the micro-electronics field.

Description

1. Technical field [0001] The invention relates to a functional ceramic material, especially a piezoelectric material and a processing method thereof, in particular to a lead-free piezoelectric thin film material and a preparation method thereof. 2. Background technology [0002] Piezoelectric material refers to the material with piezoelectric effect, and its main characteristic is electrostriction, that is, the material will deform due to the change of electric current. Because of this characteristic, piezoelectric materials have become important functional materials, and they have been widely used in dielectric materials, sensors and actuators. The integration of piezoelectric ceramics will have a wider range of applications. It can be used as a material for phase shifters, delay lines, adjustable filters and non-volatile piezoelectric memories in microelectronics technology. Actuator and sensor materials. Piezoelectric thin film materials have become an important choice...

AI Technical Summary

Problems solved by technology

At present, the sol-gel method to prepare BaTiO 3 The base piezoelectric film uses acetylacetone as a chelating agent, but the viscosity of the sol prepared by using acetylacetone as a chelating agent is too high, so it is not easy to form a film

Films prepared by the sol-gel method, due to the existence of internal stress, use improper heating or cooling rates during annealing, which may easily cause film cracking

In addition, there are still some important problems to be solved in order to obtain practical piezoelectric films, especially environmentally friendly piezoelectric films. For example, compared with bulk materials, the total resistance of films will decrease due to the much reduced thickness. , the insulation becomes poor, that is, the leakage current becomes larger; the film is prone to microcracks when the temperature is high, etc.

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