Characteristics of magnetic domain deflection of Tb0.3Dy0.7Fe2 alloy

In order to expand the applications of giant magnetostrictive materials in the field of precision positioning, an extreme value model of free energy was established with deflection angle of magnetic domain as the independent variable from the microscopic aspect. The model was based on Stoner-Wohlfarth (S-W) model wherein Tb0.3Dy0.7Fe2 alloy was taken as a research object, and the deflection law of magnetization angle of single magnetic domain was studied through drawing the equipotential curves and changing curves of free energy function under different applied stresses and in different magnetic fields. Research results showed that there were three kinds of magnetization angles of single magnetic domain as for Tb0.3Dy0.7Fe2 alloy, namely 35.26 degrees, 90 degrees and 144.74 degrees; under the action of applied stresses, the magnetization angles theta were deflected to the direction of 90 degrees for the magnetic domains of 35.26 degrees and 144.74 degrees and the magnetization angles psi were changed and transited to the direction of psi=135 degrees for the magnetic domain of 90 degrees; the magnetic domain was deflected under the action of small magnetic field for magnetic domain of 35.26 degrees; with the increase of magnetic field intensity, the magnetic domain of 90 degrees had a transition trend to a stationary planar of psi=psi(0); the magnetic domain of 144.74 degrees had a transition trend to the direction of magnetic domain of 35.26 degrees. These results laid a foundation for the magnetostrictive mechanism and establishment of precision positioning theories of the giant magnetostrictive materials.