High-Isotropic Magnetic Sensor Based on Ring Terfenol-D/PZT Composites.

In this paper, we study the isotropic properties of a ring-shaped magnetoelectric composites made of Terfenol-D and PZT-5H. We presented a theoretical model to estimate the output via areal strain considering the effect of magnetic hysteresis. Test samples were prepared by stacking and bonding together both the ring-shaped magnetostrictive material, Terfenol-D, and the piezoelectric material, PZT-5H. The results show that the magnetoelectric composites have an ac resonant frequency $f_{\mathrm {ac}}$ of about 32 kHz. When the dc bias magnetic field $H_{\mathbf {dc}} = 280$ Oe and $f_{\mathrm {ac}} = 32$ kHz, the linear fit of the relation between the output and the ac magnetic field provides a high coefficient of determination (R-square = 0.95), and the magnetoelectric voltage coefficient is 4.28 V/ $\text {cm}\cdot \text {Oe}$. These values indicate a good linear relationship, thus confirming that the composites present the basic performance of a magnetic sensor. The isotropic properties of the sample were fitted with the curve obtained from the theory. The results show that the isotropic ratio is theoretically equal to 7:1 at a resonant frequency of 32 kHz, which keeps highly consistent with test data. The coefficient of determination (R-square = 0.94) between the test data and calculated values confirms the goodness of the fit, thus indicating the correctness and reliability of the theoretical model. The model presented in this paper provides a theoretical basis to analyze and improve the isotropic properties of magnetoelectric sensors. [ABSTRACT FROM AUTHOR]