What is giant magnetoresistance used for?

What is giant magnetoresistance used for?

The main application of GMR is in magnetic field sensors, which are used to read data in hard disk drives, biosensors, microelectromechanical systems (MEMS) and other devices. GMR multilayer structures are also used in magnetoresistive random-access memory (MRAM) as cells that store one bit of information.

What is magnetoresistance explain?

Magnetoresistance is the change in resistance corresponding to an applied electric field because of the effects of a simultaneously applied magnetic field. In the Hall-effect geometry, to be specific, it means a change in electrical resistance corresponding to an electric field Ex because of Bz.

What is the cause of magnetoresistance?

The force on a current-carrying wire in a perpendicular magnetic field is due to the force on the charge carriers moving through the wire. 12. This force on the charge carriers produces an increased resistance as the charge carriers collide more with atoms in the wire. This phenomenon is called magnetoresistance.

How do you calculate magnetoresistance?

In a semiconductor with a single carrier type, the magnetoresistance is proportional to (1 + (μB)2), where μ is the semiconductor mobility (units m2·V−1·s−1 or T −1) and B is the magnetic field (units teslas).

What is the difference between GMR and CMR?

From the beginning, it will become clear that a key difference between CMR and giant MR (GMR) is that the former deals with intrinsic effects of a material, and concomitant magnetic fields that are typically large compared with those needed for real applications.

Who discovered GMR?

It has been almost 30 years since one of the most fascinating advances in solid state physics occurred, the discovery of the giant magnetoresistance effect (GMR) by Grünberg and Fert in 1988 [1,2].

What is magnetoresistance of semiconductor?

The Extraordinary Magnetoresistance (EMR) effect is a change in the resistance of a device upon the application of a magnetic field in hybrid structures, consisting of a semiconductor and a metal.

What is positive and negative magnetoresistance?

For the case of a positive magnetoresistance the junction conductance will decrease with increasing magnetic field, whereas for a negative magnetoresistance it will increase with field.

How do AMR sensors work?

In simplified form, a magnetoresistive sensor functions as follows: An object with its own magnetic field approaches the sensor. As a result, the electrical resistance changes. This makes it possible to detect at what angle the external magnetic field (and thus the object) is positioned in relation to the sensor.

What did Albert Fert discover?

Independently of one another, Albert Fert and Peter Grünberg discovered the phenomenon Giant Magneto Resistance (GMR) in 1988.

Who discovered giant magnetoresistance?

Albert Fert
In 1988, Albert Fert and his coworkers discovered a giant magnetoresistance effect (about 50% change in resistance) in Fe/Cr multilayers (see Figure 3) (Phys.

Why is it called giant magnetoresistance?

Giant magnetoresistance is the large change in electrical resistance of metallic layered systems when the magnetizations of the ferromagnetic layers are reoriented relative to one another under the application of an external magnetic field.