One-Dimensional Magnonic Crystal for Magnetic Field Sensing

Magnetic field sensor capacity of one-dimensional magnonic crystals was investigated. The surface of YIG film was modulated by periodic Cu stripes and magnet array in one dimension. The surface modulations of YIG film form sharp band gaps, since magnetostatic surface wave (MSSW) propagates through the surface of a magnetic material. It was found that a very small magnetic field change leads to a large change in the peak value of band gap frequency. A 1-Oe change in the field caused nearly 2.7 and 2.6 MHz shift in the band gap frequency for magnonic crystals modulated by periodic Cu stripes and magnet array, respectively, which means that a very low magnetic field change could be detected. Such a large shift in the band gap frequency makes these one-dimensional magnonic crystals attractive candidates for magnetic field sensing.