Common magnetism, force and electricity effects

1) Electromechanical effects: positive piezoelectric effect, piezoresistive effect, Wideman effect

2) Electromechanical effects: inverse piezoelectric effect and electrodynamic effect

3) Magnetic-machine effects: magnetostrictive effect, etc.

4) Magnetoelectric effects: Hall Effect, magnetoresistance effect, Surieffect, magnetic induced electric effect and kelvin effect.

5) Machine-magnetic effects: magnetoelastic effect, etc.

6) Electromagnetic effects: electromagnetic effect and electromagnetic induction effect

 

 

Definition of effects

1) Hall Effect: If the ends of a metal or semiconductor wafer have control current I, the magnetic field with the magnetic induction intensity of B is applied in the vertical direction of the wafer, the electromotive force U_H (Hall electromotive force or Hall voltage) will be generated in a direction perpendicular to the current and the magnetic field (i.e. between Hall outputs), which is called Hall effect.

 

Where, R_H is the Hall constant, I is the control current, B is the magnetic induction intensity, and d is the thickness of Hall component.

 

2) Magnetostrictive Effect: Under the action of external force (or stress, strain), the magnetostrictive material causes internal deformation, generating stress, which causes the boundary between the magnetic domains to move, and the magnetic domain magnetization vector rotates, changing the magnetization intensity and the permeability of the material accordingly. This phenomenon that the magnetic properties of the magnetic material change due to stress is called a piezomagnetic effect, which is also called an inverse magnetostrictive effect.

 

3)Magnetostrictive Effect: A phenomenon that some ferromagnets and their alloys, as well as some ferrites undergo mechanical deformation under the action of an external magnetic field is called magnetostrictive effect or Joule effect.

 

4) Wideman Effect: A special case of the magnetostrictive effect. When a longitudinal and a toroidal magnetic field are simultaneously applied to a ferromagnetic rod of a ferromagnetic body, the ferromagnetic rod undergoes a distortional deformation in addition to stretching change in the longitudinal direction. This physical phenomenon is called the Wideman effect.

 

5) Inverse Wideman Effect: When the ferromagnetic rod placed in a toroidal magnetic field is subject to longitudinal current and the ferromagnetic rod is subject to stretch (compress) or twist, the longitudinal magnetic flux will generate in the rod. This phenomenon is called the converse Wideman effect.

 

6) Barkhausen Effect: The ferromagnetic material produces a Barkhausen jump during magnetization, which causes the magnetic field in and around the material to change accordingly. An electromotive force is induced in a coil placed in a magnetic field.

 

7)Magnetoresistivity (MR): When a magnetic field is applied perpendicularly to the surface of an energized semiconductor, not only the Hall electromotive force but also the resistance on ends of the semiconductor will change. This phenomenon is called the magnetoresistance effect.

 

8) Giant Magneto-impedance Effect: A phenomenon that the impedance of the sensitive material varies significantly with the external magnetic field under the excitation of higher frequency current, which is referred to as GMI (Giant Magneto-impedance) effect.

 

9)  A magnetoresistance effect due to the different directions of current and magnetization.

 

10) Giant Magnetoresistance (GMR) Effect: A phenomenon that the resistivity of a magnetic material has a great change with and without external magnetic field.

 

11) Kelvin Effect: A phenomenon that inductive action causes uneven current distribution on the conductor cross section, and the closer to the conductor surface, the greater the current density.