The influences of stress on the electron band structure, the electron density of states, and the atomic magnetic moment are analyzed.
The essence of magnetic domain is an ordered arrangement of atomic magnetic moment in a small region, and its formation and existence are determined by interaction of various energies.
The magnetic properties of ferromagnetic material are determined by the atomic magnetic moment which is determined by the spin movement and distribution of electron.
Calculation of Atomic Magnetic Moment. The variation features of the magnetic characteristics of ferromagnetic materials under different external stresses have been qualitatively analyzed by calculating the electron band structure and density of states.
It can be seen from Figure 5 that the atomic magnetic moment linearly decreases with the increasing external stress at early stage and there is an inflection point in the curve when the stress increases to 15 MPa.
The magnetization of materials is related to the atomic magnetic moment. The relationship between the atomic magnetic moment and magnetization intensity M is as follows:
In the formula, [[mu].sub.j] is the atomic magnetic moment, V is the solid volume, and [summation][[mu].sub.j] is the sum of all the atomic magnetic moments in solid.
The primary cause of magnetic memory effect formation is that the stress causes the variation of the magnetic susceptibility and atomic magnetic moment of ferromagnetic material.
Such measurements have been used to determine the spatial arrangement and directions of the atomic magnetic moments, the atomic magnetization density of the individual atoms in the material, and the value of the ordered moments as a function of thermodynamic parameters such as temperature, pressure, and applied magnetic field.
The traditional role of magnetic neutron scattering is the measurement of magnetic Bragg intensities in the magnetically ordered regime, which can be used to determine the spin configuration and directions of the atomic magnetic moments as a function of temperature, pressure, and applied magnetic field, on single crystals samples, powders, thin films and artificially grown multilayers (1).