X-ray detected ferromagnetic resonance in thin films

. We discuss the physical content of X-ray Detected Magnetic Resonance (XDMR), i.e. a novel spectroscopy which uses XMCD to probe the resonant precession of the local magnetization in a strong microwave pump field. We focus on the simplest case of a steady-state precession of elemental moments in the non-linear regime of angular foldover. Like XMCD, XDMR is element and edge selective and could become a unique tool to investigate how precessional dynamics can locally affect the spin and orbital magnetization of p- or d-projected DOS. This should be possible only in the limit where there is no overdamping due to ultrafast orbit-lattice relaxation.