Study of the spin-wave resonance in a superconductor with paramagnetic impurities

The spin dynamics of paramagnetic impurities in a superconductor in the presence of external magnetic field is studied both theoretically and experimentally. The spectrum simulation with involving the mw energy absorption by unhomogeneous spin-wave excitations gives a satisfactory description of these dependences. The spin stiffness coefficient and temperature dependence of lanthanum spin susceptibility are determined