Spin wave amplification in magnetically ordered crystals

The review deals with the macroscopic approach to the s—f exchange interaction of electrons in ordered and disordered magnets. Attention is focused on the exchange amplification of spin waves in a crystal with antiferromagnetic order under electron drift. Various accompanying effects as well as the radioelectric effect due to s—f exchange and magnetoplasma phenomena, are treated. A microscopic theory is constructed to explain the amplification of spin waves in a quantizing magnetic field.