Chapter 1 - Physics of Giant Magnetostriction

Abstract

The chapter describes the physics of giant magnetostriction as the deformation of a body in response to a change in its magnetization. The change can be brought by the change in temperature or by the application of a magnetic field. All magnetic materials exhibit magnetostriction to some degree, but giant magnetostriction occurs in a small number of materials containing rare earth elements. The mechanical strength of giant magnetostrictive is important as it is used in resonance in which the amplitude of the stress can be extremely high. Magnetoelasticity is defined as the coupling between the classical properties of elasticity, strain, the intrinsically quantum mechanics, and the relativistic phenomena of magnetism. Coupling that exists at the individual electron level is known as “spin-orbit coupling.” This is one of the smallest energies used to describe the state of an atom as it derives from the relativistic aspects of the electron motion. The chapter also discusses some simplified descriptions of magnetism and magnetostriction that form a base for understanding the potential and limitations of materials exhibiting giant magnetostriction.