Magnetoelectroacoustic surface wave devices based on negative Poisson's ratio magnetostrictive substrates

Abstract

A magnetoelectric acoustic surface wave device based on a negative Poisson's ratio magnetostrictive substrate belongs to the technical field of electronic information functional materials and devices. The magnetoelectroacoustic surface wave device includes a magnetostrictive substrate, a piezoelectric film and an interdigital transducer, and the magnetostrictive substrate is a magnetostrictive material with a negative Poisson's ratio and an auxetic effect, and its thickness is greater than 2 Acoustic surface wave wavelength. In the magnetoelectroacoustic surface wave device provided by the present invention, the magnetostrictive block material with negative Poisson's ratio and auxetic effect is used as the magnetostrictive substrate, and the thickness of the substrate can reach millimeter level, which effectively improves the performance of the piezoelectric film. Thickness limitation; the magnetoelectric acoustic surface wave device provided by the present invention can significantly improve the operating center frequency f of the device while obtaining a piezoelectric film with excellent orientation 0 , so that the back-end frequency counter can more accurately test the change of the center frequency with the magnetic field, which is conducive to improving the sensitivity of magnetic field detection.

Description

technical field [0001] The invention belongs to the technical field of electronic information functional materials and devices, in particular to a magneto-electroacoustic surface wave device based on a negative Poisson's ratio magnetostrictive substrate and a preparation method thereof, which can be used for magnetic field sensing and detection or magnetic field tuning. Surface wave filters, resonators, delay lines, etc. Background technique [0002] With the continuous deepening of the research on the magnetic field and related phenomena, the magnetic sensing technology has been greatly developed. Traditional magnetic field sensors mainly include coils, Hall devices, fluxgates, magnetoresistive sensors, optical pumps, proton magnetometers, superconducting quantum interferometers, etc. Among them, the detection sensitivities of coils, Hall devices, and magnetoresistive detection are relatively low ; Although the proton magnetometer has high sensitivity, the power consumptio...

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Problems solved by technology

However, this type of magneto-electroacoustic surface wave resonator still has the following three problems: 1) what is currently used is a magnetostrictive amorphous strip such as FeB, FeSiB, FeSiBC or FeCoSiB, and this type of strip is made by melting The thickness is generally about 20 μm, which is thin and brittle, and the substrate machining problem is serious; 2) The thin magnetostrictive amorphous strip becomes thinner after grinding and polishing, and deposited on it The thickness of the piezoelectric film cannot be too large, otherwise the substrate will be bent due to the stress accumulation effect. However, when the piezoelectric film is thinner, it cannot form a sufficient orientation texture, which limits its piezoelectric coefficient and electromechanical coupling coefficient;3 ) Most importantly, the center frequency of the magnetoelectroacoustic surface wave resonator is limited by the center frequency (f 0 ) and piezoelectric layer thickness (h 压电 ), for the selected thickness, there is a cutoff frequency, Rayleigh waves cannot be excited above the cutoff frequency, and the device cannot work normally, which limits the use of such devices for magnetic field tuning filters, resonators, delays The operating frequency of the line also reduces the sensitivity for magnetic field detection and sensing

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