| The magnetoelectric composite structure has the advantages of low power consumption,small size,easy integration,etc.It shows good application prospects in many fields such as weak magnetic field detection,wireless communication,and information storage.The magnetoelectric response at the resonance frequency of the magnetoelectric composite structure is several orders of magnitude higher than that at the non-resonance frequency,but in practical applications,the device operating frequency is often not near the resonance frequency,and the resonance peak is usually narrow in bandwidth.These factors limit the magnetic The performance of electrical composite structure.In response to the above problems,a magnetoelectric composite structure with Ni Ti alloy as the substrate is designed and prepared in this paper.The temperature field controls the gradual transformation of Ni Ti alloy between low-mode martensite and high-mode austenite to change the magnetoelectricity.The mechanical properties of the composite structure can adjust the resonant frequency of the device in a wide range to achieve a controllable continuous change of the resonant point,and improve the response output and resonant bandwidth of the device by connecting multiple magnetoelectric units in series and parallel.First of all,using niobium magnesium lead titanate(PMN-PT)and iron cobalt borosilicate(Metglas)with excellent single performance as the piezoelectric phase and magnetostrictive phase materials,combined with Ni Ti alloy substrate to construct a cantilever type magnetic Electric composite structure.Through COMSOL finite element simulation,the continuous frequency modulation performance of the magnetoelectric composite structure based on the martensite transformation of Ni Ti alloy substrate was explored.The simulation results show that the Ni Ti alloy magnetoelectric composite structure has excellent temperature field controllability,and the maximum frequency modulation range of the resonance frequency can reach 19.09%.In addition,the effects of the composite structure parameters(substrate thickness,functional layer length,etc.)on the device's magnetoelectric response,resonance frequency,and frequency modulation amplitude are analyzed in depth,and the structure of the magnetoelectric composite material is optimized.Then,a Ni Ti alloy substrate magnetoelectric composite structure with various size parameters was prepared by epoxy bonding process,and its magnetoelectric response and resonance frequency adjustment performance were tested.The results show that the optimal DC bias magnetic field of the unit magnetoelectric composite structure is 27.548 Oe,the output response voltage at the resonance frequency of 4960 Hz is 197.32 m V,and the maximum magnetoelectric response coefficient is 1.789 V/cm·Oe.In the temperature range of 10? to 65?,the resonance frequency of the unit magnetoelectric composite structure can be adjusted from 4540 Hz to 4930 Hz,the frequency modulation amplitude is 8.81%,and the continuous frequency modulation performance is excellent.Finally,from the theoretical and experimental aspects,the effects of different connection methods of multiple magnetoelectric composite structural units on the output response and response bandwidth are studied.The test results show that the magnetoelectric output response of three units in series is about 2.06 times that of a single unit,and the resonance frequency band is expanded by 54% after three units are connected in parallel.In addition,adjusting the resonant frequency of the parallel structure through the temperature field can further effectively broaden the frequency band.When the unit modulation temperature is30?,40? and 50?,the 3d B bandwidth is increased by 57.6%,52.3% and 88.8%respectively,which is the future adjustable frequency The design and preparation of the magnetoelectric composite structure array laid the foundation. |
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