Search results
Results From The WOW.Com Content Network
Magnetic domain theory was developed by French physicist Pierre-Ernest Weiss [1] who, in 1906, suggested existence of magnetic domains in ferromagnets. [2] He suggested that large number of atomic magnetic moments (typically 10 12-10 18) [citation needed] were aligned parallel. The direction of alignment varies from domain to domain in a more ...
The phenomenon of hysteresis in ferromagnetic materials is the result of two effects: rotation of magnetization and changes in size or number of magnetic domains.In general, the magnetization varies (in direction but not magnitude) across a magnet, but in sufficiently small magnets, it doesn't.
Within each domain, the spins are aligned, but if the bulk material is in its lowest energy configuration (i.e. "unmagnetized"), the spins of separate domains point in different directions and their magnetic fields cancel out, so the bulk material has no net large-scale magnetic field. Ferromagnetic materials spontaneously divide into magnetic ...
The wider the outside loop is, the higher the coercivity. Movement on the loops is counterclockwise. Coercivity, also called the magnetic coercivity, coercive field or coercive force, is a measure of the ability of a ferromagnetic material to withstand an external magnetic field without becoming demagnetized.
The Wiegand effect is a macroscopic extension of the Barkhausen effect, [2] as the special treatment of the Wiegand wire causes the wire to act macroscopically as a single large magnetic domain. The numerous small high-coercivity domains in the Wiegand wire outer shell switch in an avalanche, generating the Wiegand effect's rapid magnetic field ...
Usually only the hysteresis loop is plotted; the energy maxima are only of interest if the effect of thermal fluctuations is calculated. [1] The Stoner–Wohlfarth model is a classic example of magnetic hysteresis. The loop is symmetric (by a 180 ° rotation) about the origin and jumps occur at h = ± h s, where h s is known as the switching field.
Hysteresis loop Induction B as function of field strength H for H varying between H min and H max; for ferromagnetic material the B has different values for H going up and down, therefore a plot of the function forms a loop instead of a curve joining two points; for perminvar type materials, the loop is a "rectangle" (Domain Structure of Perminvar Having a Rectangular Hysteresis Loop, Williams ...
In polycrystalline ferromagnetic materials, the AMR can only depend on the angle φ = ψ − θ between the magnetization and current direction and (as long as the resistivity of the material can be described by a rank-two tensor), it must follow [12] = + where ρ is the (longitudinal) resistivity of the film and ρ ∥, are the ...