Magnetic Properties of Magnetoplasmonic Crystals Based on Commercial Digital Discs

Several topics of photonics are targeted at the enhancement of magneto-optical response in the nanostructures. One of the approaches is creating of the magnetoplasmonic crystals based on the substrates made of the digital discs (CD, DVD, BD) with ferromagnetic film. It is necessary to investigate in-plane anisotropy of magnetoplasmonic crystals and influence of the ferromagnetic layer thickness on increase of the mean free path of edge magnetoplasmons. Ni-based magnetoplasmonic crystals were investigated using the vibrating sample magnetometer by LakeShore. All samples had anisotropic in-plane magnetic properties because of the induced anisotropy caused by the stripe-like periodic structure of the substrates. A step-like behaviour of the hysteresis loops in case of the transverse plasmon propagation way was observed for Ni-based magnetoplasmonic crystals. Measurements along the plasmon propagation way showed near-rectangular hysteresis loops typical for the Ni-based thin films for certain samples. Step-like behaviour of the hysteresis loops for the Ni-based magnetoplasmonic crystals can be explained as a result of interaction between Ni films that covered the top and the lateral sides of the substrate stripes.