  We consider the mechanism of elastic strains and stresses as the main
controlling factor of structure change under the influence of temperature,
magnetic field, hydrostatic pressure. We should take into account that the
energy of elastic deformation is commensurate to the energy of electric
interactions and that is much higher than the rest of the bonds of lower energy
value. Besides, the energy elastic stresses are of long range, so it forms the
linearity in magnetization and bulk change. These regularities requires a
fundamental understanding of the laws of interaction with respect to accepted
interpretation of quantum mechanical forces of short range that are attributes
of magnetism formation. Due to the high sensitivity of electronic and resonance
properties with respect to small changes of the structure, we were able to
define the direct relation between elastic stresses and field-frequency
dependencies, as well as to analyze the evolution of the dynamics of phase
transitions and phase states. A cycle of studies of the influence of
hydrostatic pressure on the resonance properties are presented also. The
analysis of the effect of magnetic, magneto-elastic and elastic energy allowed
us to define the combinations of magneto-elastic interactions. The role of
elastic stresses in the linear changes of the magnetostriction, magnetization,
magnetoelasticity of single-crystal magnetic semiconductors is described in
details.
