Magnetic sensor based on spin waves

Abstract

The spectrum of spin waves (SW) of tangentially magnetized films of yttrium iron garnet (YIG) with a surface metastructure in the form of gratings of etched grooves with a period close to the film thickness d (~ d) has been experimentally and numerically studied. It has been found that the spectrum of the signal reflected from a microstrip transducer with a width w>> d, located on the YIG film contains absorption lines associated with the excitation of the SW of the surface metastructure. In the case when the magnetic field H and the transducer are oriented along the grooves, the absorption lines of the metastructure are located at frequencies f* near the short-wavelength edge of the spectrum of the surface magnetostatic (Damon--Eshbach) wave fs. It is shown that f* linearly depends on H, which can be used to develop magnetic field sensors. The results of measurements of dependences f*(H) are in qualitative agreement with the results of micromagnetic modeling. Keywords: magnetostatic waves, one-dimensional grating, surface structure, sensor of magnetic field.