The angle dependent ΔE effect in TiN/AlN/Ni micro cantilevers

Abstract

In this work, magnetoelectric MEMS sensors based on a TiN/AlN/Ni laminate are investigated for the first time in regards of the anisotropic elastic properties when using hard magnetic Nickel as magnetostrictive layer. The implications of crystalline, uniaxial and shape anisotropy are analysed arising from the anisotropic Δ E effect in differently oriented cantilevers with 25 µm length and 15° spacing. The Δ E effect is derived analytically to consider the angular dependency of the different anisotropies within the sensors. In the measured frequency spectra complex profiles are observable consisting of contributions from neighbouring structures which are connected by a common electrode. The crosstalk effect is strongly depending on the cantilever orientation and reflects the anisotropic mechanical properties of the material stack. The intensity of the crosstalk effect is increasing for shortened cantilevers and narrowing distance between structures. The Δ E effect is investigated based on cantilevers of different angular spacing and of a single cantilever that is rotated in the magnetic field. The derived peak sensitivities are reaching values of 1.15 and 1.31 T −1 . The angular dependency of the sensitivity is found to be approximately constant for differently oriented cantilevers. In contrast, for a singly rotated cantilever an angular dependency of the 4th order is observed. • Δ E effect related eigenfrequency change can be described by uniaxial magnetic anisotropy. • sensitivity differs for single rotated cantilever compared to differently oriented ones. • observed crosstalk effect is depending on structure length, orientation and spacing.