Magnetoresistance and Its Types(PPT)

The slides include basic information about magnetoresistance its discovery, types and applications

1. MAGNETORESISTANCE
AND ITS TYPES
BY: M ZUBAIR ARSHAD
UNIVERSITY OF EDUCATION
LAHORE

2. Contents To Be Covered
History of Magnetoresistance
Definition
Working Principle
Types
Application
Future works and its implications

3. HISTORY:
In1856WilliamThomson(knownasLord
Kelvin)discoveredthemagnetoresistance
(OMR).
He uses iron pieces for his work.
Later replace iron with Nickel.
He was able to lower the resistance up to 5 %.

4. Magnetoresistance:
Thepropertyofthedevicewhoseelectricalresistancecanbechanged
whenitisplacedinanexternally-appliedmagneticfield.
So,itcanbesaythisisthetypeofresistorwhoseresistancevariesafter
applyinganexternalmagneticfield.
Symbol/CircuitDiagram:
Magnetoresistor Symbol

5. Working Principle:
Magnetoresistancework on the principle of
electrodynamics.
|??????
??????| = q |V||B|sinθ
Resistance of material ∝Strenghtof
Magnetic Field

6. Types of Magnetoresistor
Giant Magnetoresistance(GMR)
Extraordinary Magnetoresistance(EMR)
Tunnel Magnetoresistance(TMR)

7. Giant Magnetoresistance(GMR)
PeterGrunbergandAlbertFert(1988)
Multilayersofnon-magneticand
ferromagneticconductivelayers
Dependstwoadjacentlayersof
ferromagneticmaterialareparallelor
anti-parallel

8. Extraordinary Magnetoresistance(EMR)
Discoveredin2000
EMReffectismoreeffectivethanGMR
Semiconductor-metalshybridsystem
ObservedinTraversedMagneticField
Atroomtemp.itshowslowerresistance

9. Tunnel Magnetoresistance(TMR)
Discoveredin1975byMichelJulliere
ConstructionissimilartoGMRbutthiseffectisobservedinmagnetic
tunneljunction(MTJ)madeupofathinlayerofaninsulatorandtwo
magneticmaterials
Dependsonthedirectionofmagnetization

10. Applications
MRAM
Hard Disc Drive
Magnetometer
Ferrous Detection
Electronic Compass
Bio-Sensors, Position Sensors, Magnetic
Sensor

11. Future Implications
Discoveryofinsulator-ferromagneticbilayershasimportantimplications
forthesemiconductorindustryandenablinglowpowercomputingchipsfor
robotsandbrain-likecomputinginthenearfuture.
Thehuman-computerinteractionsystems,thesensor-controlledwheelchair
commandedbytheheadmovement.
ImprovinginBiomedicinedevices.
Thescientistwentonthattheapplicationofmagnetoresistivetechnologyis
promisinginsuchflexibleportableelectronicgadgetslikesmartphones,
wristbandsetc.

12. REFERENCES
Magnetoresistancein metals by A. B Pippard1
st
edition
www.researchgate.net.com
www.physics-and-radio-electronics.com
www.Wikipedia.org

13. Q ??????A