AN INSITU SCANNING ELECTRON-MICROSCOPE KOSSEL X-RAY-DIFFRACTION STUDY OF THE ELASTIC AFTEREFFECT IN A FERROELASTIC ALLOY

Ferromagnetism arises from the orientation of magnetic moments. Magnetic moments are due mainly to the ordering and coupling of electron spins and partly to changes in electron orbits. Ferroelectricity, a term first used to describe properties of barium titinate, arises from the orientation of electric moments associated with ions. Ferromagnetism and ferroelectricity are each accompanied by small, well-defined elastic displacements of atoms or ions, which impart a lowering of crystal symmetry to the host lattice, from cubic to tetragonal in the case of ferromagnetism in iron, for example. Such deformations are reversible and are not uncommonly referred to as "ferroelasticity. " © 1990 The Metallurgical of Society of AIME.