Currently, the surface acoustic wave (SAW) magnetic field sensing technique utilises the SAW velocity/frequency mechanism of magnetoacoustic interaction as an indicator of the magnetic sensitivity mechanism. However, this method has low sensitivity and poor stability. To address this problem, a dynamic magnetoelastic coupling theoretical model is constructed to theoretically simulate the influence of the ΔE effect of magnetically sensitive thin films on SAW propagation attenuation. This study describes a high-sensitivity SAW magnetic field sensing mechanism based on magnetoacoustic attenuation. The simulation results show a clear relationship between the acoustic propagation loss and external magnetic field, indicating a structure-property relationship. An amorphous soft magnetic material (Fe₉₀Co₁₀)₇₈Si₁₂B₁₀ was used as a magnetically sensitive thin film due to its high permeability, low coercivity (Hc), low hysteresis, ease of magnetisation and demagnetisation. SAW magnetosensitive device operating on a frequency of 200 MHz has been experimentally developed using a standard semiconductor photolithography process. A SiO₂ layer was deposited on a 36° YX-LiTaO₃ substrate as a waveguide, and a (Fe₉₀Co₁₀)₇₈Si₁₂B₁₀ layer was on the top of the propagation area as a magnetosensitive film. The experimental results showed that the acoustic loss change due to the magnetic field variation was 4.63 dB within a magnetic field range of 0 Oe to ±10 Oe, which agreed with the theoretical results. The sensor had a sensitivity of 0.7546 dB Oe⁻¹ within the range of 0–4 Oe and the lower detection limit of magnetic fields was 0.272 Oe, low hysteresis error of 0.54%, multiple repeatability error of 0.13%, excellent repeatability and stability were achieved in the experiments from the developed sensing device.

中文翻译：

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基于损耗机制的高灵敏表面声波磁场传感器

目前，表面声波（SAW）磁场传感技术利用磁声相互作用的SAW速度/频率机制作为磁灵敏度机制的指标。但该方法灵敏度低、稳定性差。针对这一问题，构建了动态磁弹性耦合理论模型，从理论上模拟了Δ的影响。乙磁敏薄膜对 SAW 传播衰减的影响。本研究描述了一种基于磁声衰减的高灵敏度 SAW 磁场传感机制。模拟结果显示声传播损耗与外部磁场之间存在清晰的关系，表明结构与性能之间的关系。非晶软磁材料(Fe ₉₀ Co ₁₀ ) ₇₈ Si ₁₂ B ₁₀由于其高磁导率、低矫顽力(Hc)、低磁滞、易于磁化和退磁而被用作磁敏薄膜。工作频率为 200 MHz 的 SAW 磁敏器件已使用标准半导体光刻工艺进行实验开发。在36°YX-LiTaO ₃基板上沉积SiO ₂层作为波导，在传播区域顶部沉积(Fe ₉₀ Co ₁₀ ) ₇₈ Si ₁₂ B ₁₀层作为磁敏膜。实验结果表明，在0 Oe到±10 Oe的磁场范围内，由于磁场变化引起的声损耗变化为4.63 dB，与理论结果一致。该传感器在0~4 Oe范围内灵敏度为0.7546 dB Oe ⁻¹ ，磁场检测下限为0.272 Oe，磁滞误差低至0.54%，多次重复性误差为0.13%，具有良好的重复性和稳定性。在开发的传感装置的实验中实现了这一点。