Stress Dependence of Seebeck Coefficient in Iron-Based Amorphous Ribbons

Abstract

The results of an investigation on tensile stress dependence of mean Seebeck coefficient in Fe-based amorphous ribbons are presented, constituting a new Seebeck-sigma effect. A measurement test stand, capable of the determination of small variations in thermopower in such materials under stress is described. Exemplary results for commercially available, positively magnetostrictive SA1 and 2605CO amorphous ribbons show significant stress dependence with more than 1% of relative change, in contrast to negatively magnetostrictive 6030D alloys with 0.1% change. Non-ferromagnetic alloys are tested for comparison purposes, giving negligible results. Thus, the possibility of a magnetomechanical mechanism of the stress influence is proposed.

Novel Giant Magnetoimpedance Magnetic Field Sensor

“…The excitation signal had a frequency of Careful sample mounting ensured the small influence of stress on the results; this is particularly important due to the GMI-related [38] the stress-impedance effect (i.e., a change in the sample impedance under the influence of stress-induced change in magnetic permeability) [39]. This is one of the adverse instances of the significant magnetoelastic effect in amorphous alloys [40,41], which changes the whole magnetization process due to induced anisotropy [42,43], but could be otherwise utilized [44,45]. To control the entire measuring station and acquire the measurement data, a custom application was written in the LabVIEW environment.…”

Modelling the Characteristics of Ring-Shaped Magnetoelastic Force Sensor in Mohri’s Configuration

“…Finally, the results of simulation, both magnetic flux density B vector distribution as well as mechanical stresses σ tensor were exported to text file using SaveGridData solver. It should be highlighted, that Equations (3)- (7) were implemented in the model using MATC language built into the Elmer FEM software.…”

“…Such sensors utilize the dependence of magnetic characteristics of soft magnetic materials on the mechanical stress σ [1,2], especially changes of relative permeability µ r (σ) of material. One of emerging direct µ r (σ) approaches is the SI (Stress-impedance) effect [3] and change of magnetic anisotropy direction [4], while advanced material studies show magnetomechanical influence on unbalanced small angle magnetization rotation (SAMR) [5], Matteucci [6], or even thermoelectric [7] voltage. Due to their robustness, sensitivity and reliability [8,9] magnetoelastic sensors are intensively developed for the most demanding industrial [10] and biomedical [11] applications.…”