A recent study has discovered that graphene exhibits an anomalous Giant Magnetoresistance (GMR) at room temperature. The team of researchers found that the magnetoresistance observed in the graphene-based device was almost 100 times higher than that observed in other known semimetals in this magnetic field range.
Understanding Magnetoresistance and Giant Magnetoresistance (GMR)
Magnetoresistance is the property of a material to alter the value of its electrical resistance when an external magnetic field is applied. The phenomenon of Giant Magnetoresistance (GMR) is a large change in the electrical resistance, which is induced by the application of a magnetic field to thin films composed of alternating ferromagnetic and nonmagnetic layers.
The 2007 Nobel Prize in Physics was awarded to Albert Fert and Peter Grünberg for their discovery of GMR. GMR is widely used in various applications, including hard disk drives and magneto-resistive RAM in computers, biosensors, automotive sensors, micro-electromechanical systems, and medical imagers.
Understanding the Study
The team of researchers discovered that graphene displays a remarkably high GMR effect, which is almost 100 times higher than that observed in other known semimetals in this magnetic field range. The team attributed this finding to the presence of a neutral plasma and the electrons’ mobility. The researchers explained that the neutral plasma plays a crucial role in enhancing the GMR effect in graphene, and the high electron mobility in graphene allows it to act as a superior material for magnetoresistive applications.
Applications of GMR
GMR-based devices are particularly used to sense magnetic fields. Some of the applications of GMR include:
Hard disk drives: GMR is used in hard disk drives to read and write data. Magneto-resistive RAM: GMR is used in magneto-resistive RAM in computers, which is faster and more efficient than traditional RAM.
Biosensors: GMR-based biosensors can detect biomolecules and viruses, making them an essential tool for medical research.
Automotive sensors: GMR-based automotive sensors can detect changes in magnetic fields and are used in anti-lock braking systems, electronic stability control systems, and other safety applications.
Micro-electromechanical systems: GMR-based micro-electromechanical systems are used in accelerometers, gyroscopes, and other sensors.
Medical imagers: GMR-based medical imagers are used to detect the magnetic fields produced by the body’s organs and tissues.
Why In News
A recent study has revealed that graphene exhibits an unexpected and high level of Giant Magnetoresistance (GMR) at room temperature, almost 100 times higher than that observed in other semimetals. This discovery could lead to the development of more advanced and efficient magnetoresistive devices for use in various fields, including medical imaging, biosensors, and data storage.
MCQs about Applications of Giant Magnetoresistance
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What is the role of neutral plasma in enhancing the GMR effect in graphene?
A. It plays no role in enhancing the GMR effect
B. It reduces the GMR effect in graphene
C. It plays a crucial role in enhancing the GMR effect in graphene
D. It has a negligible effect on the GMR effect in graphene
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What are the potential applications of GMR-based devices?
A. Sensing magnetic fields and data storage
B. Sensing magnetic fields and biosensors
C. Data storage and biosensors
D. Sensing magnetic fields, data storage, biosensors, and medical imaging
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What is the significance of the discovery of graphene’s anomalous GMR effect at room temperature?
A. It has no significance
B. It could lead to the development of more advanced and efficient magnetoresistive devices for use in various fields
C. It could lead to the development of new materials for use in magnetic fields
D. It could lead to the development of new applications for semimetals
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