Diamagnetic & Paramagnetic

HistoryMagnetic needle, was used in China as early as the 13th century B.CThe early Greeks about 800 B.C, discovered the stone magnetite (Fe3O4)In 1269 a Frenchman showed that every magnet has two polesIn 1600s William Gilbert show that a compass needle orients to permanent magnet of the earthIn 1750s show that magnetic poles exert attractive or repulsive forces on each otherin 1819s Hans Christian Oersted and Andr Ampre discovered the relationship between magnetism and electricityIn 1820s Faraday and Joseph Henry further connections between electricity and magnetism

Classification of Magnetic MaterialsDiamagnetismParamagnetismFerromagnetism FerrimagnetismAntiferromagnetism

in vacuummagnetic fieldmagnetic inductionIn mattermagnetizationmagnetic susceptibilityMacroscopic description of magnetismRelative permeability

in vacuumIn matterMacroscopic description of magnetism

William D. Callister, Jr.Fundamentals Of Materials Science And EngineeringThe dependence of B on the external field H for a materialThe magnetic moment opposes the field in diamagnetic materials Progressively stronger moments are present in paramagneticMacroscopic description of magnetism

Diamagnetic MaterialsCause of Orbital motion of electrons Magnetised opposite to that of applied magnetic fieldThe value of magnetic induction B < HMagnetic susceptibility m < 0 and mr < 1Magnetic susceptibility does not depend on temperature (except H at low temperature)

Diamagnetic Materials

Diamagnetic Materialsnearly all organic substances.superconductors below the critical temperature. These materials are ideal diamagnets,(MeissnerOchsenfeld effect)intan , Cu, Ag, Au, Zn, Bi, Sb, NaCl, H2O airA few examples of diamagnetic materials are ;

Paramagnetic MaterialsCause of Spin motion of electronsMagnetised in the direction of applied magnetic fieldThe value of magnetic induction B > HMagnetic susceptibility m > 0 and mr > 1Magnetic susceptibility inversely proportional to temperature 1/T or = C/T (Curie law)

Paramagnetic MaterialsCurie Law T>T, paramagnetic

T=T,

T

Paramagnetic MaterialsAl, Mn, Pt, Na, CuCl2, O2, kacaA few examples of paramagnetic materials are ;

Diamagnetic & Paramagnetic

Applications of Magnetic MaterialsData Storage MaterialsPermanent MagnetsPower - The strength of a permanent magnet as expressed by the maximum product of the inductance and magnetic field.

ReferensiDonald R. Askeland Pradeep P. Phul. The Science and Engineering of Materials, 4th ed, chap,19Halliday-Resnick-Walker. Fundamentals of Physics. Chap;29William D. Callister, Jr. Fundamentals of Materials Science and Engineering, Ed,7http://thesis.library.caltech.edu/4188/9/Chapter_6.doc.pdfhttp://www.transtutors.com/physics-homework-help/magnetism/magnetic-materials.aspx

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