Microwave Spectroscopy of a Single Permalloy Chiral Metamolecule on a Coplanar Waveguide

We investigate the microwave spectroscopies of a micrometer-sized single permalloy (Py) chiral structure on coplanar waveguides (CPWs). Under an external dc magnetic field applied in a direction perpendicular to the microwave propagation, the Py chiral structure loaded on the center of the CPW signal line shows Kittel-mode ferromagnetic resonance. Contrastingly, the structure on the signal-line edge highlights two additional resonances: spin-wave resonance at a higher frequency, and unique resonance at a lower frequency of approximately 7.8 GHz. The resonance signal at 7.8 GHz originates from magnetically induced, geometry-driven resonance, although the resonance frequency does not depend on the external magnetic field. Moreover, the displacement of the Py structures on the signal line results in nonreciprocal microwave transmission, which is traced back to the edge-guide mode

Magnetic Polarization of Au Layers in M/Au Metallic Multilayers (M=Fe, Co, Ni) Investigated by Mossbauer Probe Atoms (SOLID STATE CHEMISTRY-Artificial Lattice Allolys)

Magnetic polarization of nonmagnetic Au layers in ferromagnetic/ nonmagnetic metallic multilayers was probed by 119Sn and 57Fe Mossbauer spectroscopy. The Mossbauer probe atoms located in the Au layer with various depths from the interface show depth-dependent large hyperfine field, indicating magnetic polarization in the Au layer. The depth profiles of the magnetic polarization are discussed in Fe/ Au, Co/ Au and Ni/ Au systems

Enhanced Magneto-Optical Activities of Modulated Fe-Pt Multilayer Metamaterials

We study optical and magneto-optical (MO) properties of epitaxially grown modulated Fe-Pt multilayer metamaterials by means of generalized MO ellipsometry (GME). Large Kerr rotation, ellipticity, and MO coupling parameters in the visible and near-infrared regions are obtained for modulated metamaterials, in which the stacking sequences follow an inverse Fibonacci series. In contrast, periodic multilayers show small MO parameters, although they otherwise exhibit magnetic and optical properties that are very similar to those for the modulated metamaterials. The present study demonstrates that specific thickness modulation can have a significant materials design potential for one-dimensional magnetic metamaterials