Structural, magnetic, and magnetostrictive properties of two-sublattice Tb _0.27Dy _0.73 (Fe _1−xAl _x) ₂ polycrystalline intermetallic ferrimagnets ( x = 0−0.2 and 1.0) were studied using X-ray powder diffraction, magnetometry, and strain gauge magnetostriction measurements. Temperature dependences of magnetization starting from 80 K were presented, and Curie temperatures were estimated. Coercive force, residual, and saturation magnetizations were determined from the magnetic hysteresis loops at room temperature. Longitudinal, transversal, form and volume magnetostrictions were investigated against the x parameter and the intensity of the magnetic field. The piezomagnetic coefficients were determined and the maximum value at the field below 1 kOe, even enhanced than that in Terfenol-D, was observed for the material Tb _0.27Dy _0.73 (Fe _0.9Al _0.1) ₂. It means that this compound is promising for use in magnetoelectric composites.

The coupling of the propagating stress wave with the eddy current model is presented. The applied stress produces magnetization in the sample that can be measured outside the sample by measuring the resulting magnetic flux density. The stress and flux density measurements are made on a mechanically excited steel bar. The problem is modelled with the finite element method for both the propagating wave and the eddy current. Three aspects are considered: eddy current model using magnetization from the measurements, coupled wave and eddy current models, and coupled different dimensions in the wave model. The measured stress can be reproduced from the measured flux density by modelling. The coupled models work both for stress and flux couplings as well as for the different dimensionality couplings.

The paper presents the novel concept of the magnetoelectric sensor constructed using the amorphous glass ribbon. Its output characteristics (voltage pattern), conditions of work and experimental results are presented. The novel construction allows for minimizing the demagnetizing field in the core of the sensor and linearization of the characteristics between the magnetic field and obtained voltage. Conducted experiments were aimed at determining the sensor operation in the presence of the constant magnetic field (HDC). The main concern of the tests was to verify the linear dependency between the HDC value and the amplitude of the output voltage. Next, the computer model representing the sensor behavior in the constant magnetic field is described. The model implements the parameter identification task based on the regression algorithms. The presented work shows that the proposed device can be used to measure the weak magnetic field and the dependency between the output signal amplitudes and the constant component in the measured magnetic field is approximately linear. This enables measurements of even weak fields.

The paper presents the analysis of the magnetic sensor’s applicability to the energy harvesting operations. The general scheme and technical advancement of the energy extraction from the electric vehicle (such as a tram or a train) is presented. The proposed methodology of applying the magnetic sensor to the energy harvesting is provided. The experimental scheme for the sensor characteristics and measurement results is discussed. Conclusions and future prospects regarding the practical implementation of the energy harvesting system are provided.