Damping, Anisotropy and Spin Wave Modes of Laser Patterned Low-Loss Ferrimagnet Vanadium Tetracyanoethylene*

Vanadium tetracyanoethylene (V[TCNE]_x; x≈2) is a low magnetic damping organic-based ferrimagnet that is compatible with a wide variety of substrates. These properties make it promising for magnonics applications requiring integration of low-loss magnetic materials with microwave circuits. Here we present the integration of patterned V[TCNE]_x with a microwave waveguide. A V[TCNE]_x film is grown on an Al₂O₃ encapsulated coplanar waveguide patterned on a sapphire substrate. The film is then encapsulated with a glass coverslip and patterned with high intensity laser illumination to selectively remove magnetism. We study the damping, anisotropy, and spin wave modes of laser patterned structures. This approach enables in situ patterning and fine tuning of the resonance modes, compensating growth to growth variation in material properties like saturation magnetization and anisotropy.