Here we report on the interplay between the magnetic, optical and magneto-optical properties of magnetoplasmonic crystals (MPC) based on the 1D diffraction gratings. A wide range of the characteristic parameters is examined to be effective for magnetic field sensor application. The gratings with periods of 320 nm and 740 nm with corresponding profile heights of 20 nm and 100 nm were used. Using ion-beam sputtering the diffraction gratings were covered by combination of following functional layers: noble metal - silver or gold with thicknesses of 50 or 100 nm; ferromagnetic metal - iron, silver, permalloy with thicknesses of 5, 20, 50, 100 nm; passivation layer of silica nitride with thicknesses of 20, 30 or 40 nm. The details of fabrication and characterization of magnetoplasmonic crystals will be discussed. We show how the 1D MPC can operate as highly sensitive and local sensor of DC magnetic field by utilizing the magneto-modulation sensor technique combined with the magneto-optical probes. As a result, the design of sensor prototype was optimized and the achieved sensitivity was found to be up to 10 μOe at a local area of 1 mm2. The main contribution to effect of MPC design on sensor parameters is geometry-driven magnetic properties formed during fabrication and depended on characteristic parameters of MPC. The developed sensor has sensitivity suitable for in biomedical applications and can be further improved by optimizing the sensing element and the sensor’s setup overall design.
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