Modern Problems in Condensed Matter Sciences, Volume 22.2: Spin Waves and Magnetic Excitations focuses on the processes, methodologies, reactions, principles, and approaches involved in spin waves and magnetic excitations, including magnetic systems, fluctuations, resonance, and spin dynamics. The selection first elaborates on spin-wave resonance in metals, excitations in low-dimensional magnetic systems, and the theory of magnetic excitations in disordered systems. Topics include spin waves in ferromagnets with weak fluctuations of the exchange interaction; dynamics of propagating excitations; models of two-dimensional magnetic systems; spin-wave resonance in bulk metals; and standing spin-wave resonance in thin films. The manuscript then ponders on spin dynamics of amorphous magnets and magnetic excitations in spin glasses, including dynamics in reentrant spin glasses, dynamics of classical spin glasses, spin dynamical theory, spin dynamics of locally isotropic materials, and effects of dilution. The book takes a look at nuclear spin and magnetoelastic excitations and magnetic impuritons in antiferromagnetic dielectric crystals. Discussions focus on coherent and incoherent impurity excitations, equations of motion and the energy of a magnetoelastic medium, magnetoelastic excitations near magnetic orientational phase transitions, and the effect of frequency pulling on the behavior of nuclear spin echo signals. The selection is a vital source of data for researchers interested in spin waves and magnetic excitations.