Torque, FMR and domain mode FMR relations in thin "Oblique anisotropy axis" films

Forms for the torque, ferromagnetic resonance (FMR) and domain mode FMR (DMFMR) relations are derived for "oblique anisotropy axis" films. The energy derivative scheme, as described by Smit and Beljers for example, is employed. Under magnetic saturation conditions, torque and FMR formulae are obtained for an applied field \vec{H} in the vertical plane containing the tilted uniaxial magnetocrystalline anisotropy axis. Shifts of the torque curve zero-crossings and of the extrema of the FMR line pattern are found. The situation when \vec{H} is in the basal plane is also addressed. For this case specific formulae are given, valid in the H/(2K/M) \gg 1 approximation. The formalism for the derivation of the DMFMR in this system under non-saturation conditions is presented. A stripe domain situation with \vec{H} in the basal plane is modeled.