Units for Magnetic Properties

Units for Magnetic Properties

Quantity Symbol Gaussian & cgs emua Conversion
factor, Cb		 SI & rationalized mksc
Magnetic flux density, magnetic induction B gauss (G)d 10-4 tesla (T), Wb/m2
Magnetic flux F maxwell (Mx), G·cm2 10-8 Weber (Wb), Volt·second (V·s)
Magnetic potential difference, magnetomotive force U, F gilbert(Gb) 10/4p ampere (A)
Magnetic field strength, magnetizing force H oersted (Oe),e Gb/cm 103/4p A/mf
Volume magnetizationg M emu/cm3h 103 A/m
Volume magnetization 4pM G 103/4p A/m
Magnetic polarization, intensity of magnetization J, I emu/cm3h 4p×10-4 T, Wb/m2i
(Mass) magnetization s,M emu/g 1
4p¥10-7		 A·m2/kg
Wb·m/kg
Magnetic moment m emu, erg/G 10-3 A·m2, joule per tesla (J/T)
Magnetic dipole moment j emu, erg/G 4p¥10-18 Wb·mi
Volume susceptibility c, k dimensionless, emu/cm3 4p
(4p)2¥10-7		 dimensionless
henry per meter (H/m), Wb/(A·m)
Mass susceptibility cr, kr cm3/g, emu/g 4p¥10-3
(4p)2 ¥10-10		 m3/kg
H·m2/kg
Molar susceptibility cmol, kmol cm3/mol, emu/mol 4p¥10-6
(4p)2¥ 10-13		 m3/mol
H·m2/mol
Permeability m dimensionless 4p¥10-7 H/m, Wb/(A·m)
Relative Permeability mr not defined   dimensionless
(Volume) energy density,
energy productk		 W erg/cm3 10-1 J/m3
Demagnetization factor D,N dimensionless 1/4p dimensionless
a Gaussian units and cgs emu are the same for magnetic properties. The defining relation is B = H + 4pM.
b Multiply a number of C to convert it to SI (e.g. 1 G ¥ 10 -4T/G = 10-4T)
c SI (Système Internation d'Unités) has been adopted by the National Bureau of Standards. Where two conversion factors are given, the upper one is recognized under, or consistent with, SI and is based on the definition B = m0H + J, where the symbol I is often used in place of J.
d 1 gauss=105 gamma (g).
e Both oersted and gauss are expressed as cm-1/2·g1/2·s in terms of base units.
f A/m was often expressed as "ampere-turn per meter" when used for magnetic field strength.
g Magnetic moment per unit volume.
h The designation "emu" is not a unit.
i Recognized under SI, even though based on the definition B = m0H + J. See footnote c.
j mr = m/m 0 = 1 + c, all in SI. mr is equal to Gaussian m
k B·H and m0M·H have SI units J/m3;M·H and B·H/4p have Gaussian units erg/cm3. 
R.B. Goldfarb and F.R. Ficket, U.S. Department of Commerce, National Bureau of Standards, Boulder, Colorado 80303, March 1985

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