Magnetoresistance

Definition

Magnetoresistance is the property of a material to change its electrical resistance in the presence of an external magnetic field. This phenomenon is observed in various materials and has important applications in the field of electronics and magnetic sensing.

5 Must Know Facts For Your Next Test

1. Magnetoresistance is a fundamental property of materials that is exploited in various electronic devices, such as magnetic field sensors, read heads in hard disk drives, and magnetic random access memory (MRAM).
2. The magnitude of the magnetoresistance effect depends on the material properties, the strength of the magnetic field, and the angle between the current and the magnetic field.
3. Anisotropic magnetoresistance (AMR) is a type of magnetoresistance where the electrical resistance of a material depends on the angle between the direction of the current and the direction of the magnetization.
4. Giant magnetoresistance (GMR) is a quantum mechanical effect observed in thin film structures, consisting of alternating ferromagnetic and non-magnetic layers, where the electrical resistance of the material depends on the relative orientation of the magnetizations in the adjacent ferromagnetic layers.
5. Magnetoresistance is a key concept in the development of modern magnetic field sensors, which are used in a wide range of applications, including navigation, position detection, and current sensing.

Review Questions

• Explain the relationship between magnetoresistance and the Hall effect.
  • Magnetoresistance and the Hall effect are closely related phenomena. The Hall effect is the production of a voltage difference across an electrical conductor transverse to an electric current and a magnetic field perpendicular to the current. Magnetoresistance, on the other hand, is the change in the electrical resistance of a material due to the presence of an external magnetic field. Both effects are a result of the interaction between the charge carriers (electrons or holes) in the material and the magnetic field, and they are often observed in the same materials and devices.
• Describe the differences between anisotropic magnetoresistance (AMR) and giant magnetoresistance (GMR).
  • Anisotropic magnetoresistance (AMR) and giant magnetoresistance (GMR) are two distinct types of magnetoresistance. AMR is a property where the electrical resistance of a material depends on the angle between the direction of the current and the direction of the magnetization. In contrast, GMR is a quantum mechanical effect observed in thin film structures consisting of alternating ferromagnetic and non-magnetic layers, where the electrical resistance of the material depends on the relative orientation of the magnetizations in the adjacent ferromagnetic layers. The magnitude of the magnetoresistance effect is typically much larger in GMR materials compared to AMR materials, making GMR more suitable for applications such as magnetic field sensors and read heads in hard disk drives.
• Analyze the importance of magnetoresistance in the development of modern electronic devices and sensors.
  • Magnetoresistance is a fundamental property that has enabled the development of numerous electronic devices and sensors with important applications in various industries. The ability of materials to change their electrical resistance in the presence of a magnetic field has been exploited in the creation of magnetic field sensors, which are crucial for applications such as navigation, position detection, and current sensing. Additionally, the discovery of giant magnetoresistance (GMR) has revolutionized the data storage industry by enabling the development of high-density hard disk drives with read heads that can detect increasingly smaller magnetic domains. Furthermore, magnetoresistive materials are being explored for use in magnetic random access memory (MRAM), which offers the potential for non-volatile, high-speed, and energy-efficient data storage solutions. The continued advancement and integration of magnetoresistive technologies are expected to drive further innovations in the field of electronics and sensing.

Related terms

Hall Effect: The Hall effect is the production of a voltage difference (the Hall voltage) across an electrical conductor transverse to an electric current in the conductor and a magnetic field perpendicular to the current.

Anisotropic Magnetoresistance (AMR): Anisotropic magnetoresistance is a type of magnetoresistance where the electrical resistance of a material depends on the angle between the direction of the current and the direction of the magnetization.

Giant Magnetoresistance (GMR): Giant magnetoresistance is a quantum mechanical effect observed in thin film structures, consisting of alternating ferromagnetic and non-magnetic layers, where the electrical resistance of the material depends on the relative orientation of the magnetizations in the adjacent ferromagnetic layers.