Static and dynamic stresses

In this chapter we shall consider the properties of lanthanide metals, their alloys and compounds which can be studied using static and alternating mechanical stresses. The main attention will be paid to the effects related to magnetoelastic interactions. These interactions in magnetic materials can display themselves in static magnetostriction deformations (this effect is not considered here) and in the changing of the magnetic state under mechanical stress. The latter causes variation of the magnetic phase transition temperatures, magnetization and magnetic structures, and leads to the appearance of anomalies in elastic constants, as well as to additional damping of sound oscillations in the lanthanide materials. The importance of understanding the nature of magnetoelastic interactions and related effects arises from the scientific desire to gather a better knowledge of magnetism, as well as from possible technological applications.