The Usage Of Magnonic Crystal As Magnetic Field Sensors

Magnonic crystals, produced for the propagation of spin waves in long range, are magnetic materials with alternating magnetic properties. The spin wave spectrum of magnonic crystals shows bands of allowed magnonic states and forbidden band gaps. The band gap width can be varied via a wide range of parameters such as; the type of magnetic material, the shape of the sample, surface profile and especially the orientation and magnitude of applied magnetic field which makes the magnonic crystals attractive materials for technological applications. In particular, the magnetic field sensitivity of band structure allows the magnonic crystals to be used as an extremely sensitive magnetic field sensor. In this thesis, one and two dimensional magnonic crytals were produced and the variation of band gap with magnetic field was investigated. Single crystal YIG thin films were use to form magnonic structure. The measurements showed that the slope of peak frequency versus magnetic field is about 37pT/Hz. This clearly indicate that the magnetic field sensor can be developed using magnonic crystal with a sensitivity of pT.