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This paper presents models developed through analytical or numerical computation and finite element analysis to improve the resolution of a new kind of vibrating magnetometers. This peculiar magnetometer uses the piezoelectric transduction to actuate a quartz resonator at its resonance frequency taking advantage of the high Q factor of a quartz resonator to achieve high resolution. The magnetic sensitive element is a thin ferromagnetic film of Nickel-Cobalt which is sputtered on the moving beams of the resonator. This magnetic thin film applies a periodic torque on the resonator, shifting its resonance frequency. This torque depends on the magnetic field applied; therefore the value of the magnetic field can be deduced from the frequency shift measurement. The aim of this paper is to develop and improve sensitivity models which will be useful tools in a future work to establish the optimal geometry for a resonator and the best position of the magnetic thin film on it in order to improve the sensitivity and resolution of the global sensor.

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Ti O x physical vapor deposition (PVD) films were studied to improve the adhesion of Pt∕AlN∕Pt piezoelectric transducers on γ-Al2O3∕NiCoCrAlY/superalloy components. Thick (1.7–3.8μm) TiOx films deposited by rf reactive cathodic sputtering on α-Al2O3 substrates were analyzed by x-ray diffraction (XRD) and scanning electron microscopy equipped with energy dispersive x-ray spectroscopy. The influence of substrate temperature (Ts), oxygen mole fraction in the plasma gas and annealing (1050°C, 1h, in air) on structural properties, morphology, and chemical composition of the films was observed. Thin (⩽10nm) TiOx adhesion layers and Pt films were sputtered on α-Al2O3. The effects of TiOx deposition parameters on the adhesion and the orientation of as-deposited and annealed Pt films were examined by tensile pull-off test and XRD, respectively. The results showed a (111) preferred orientation and good adhesion of Pt films. Finally, the selected TiOx deposition parameters were applied on γ-Al2O3∕NiCoCrAlY/superalloy substrates. Adhesion properties of annealed Pt films on γ-Al2O3 and TiOx∕γ-Al2O3 were evaluated. The results showed a drastic improvement of the pull-off force (≈0to≈100MPa) by using the TiOx “glue layer.” The adhesion layer also led to a pronounced (111) preferential orientation of the Pt films.