H
H-O
(A)
The atomic dipole configuration for a
diamagnetic material with and without a
magnetic field. In the absence of an external
field, no dipoles exist; in the presence of a
field, dipoles are induced that are aligned
opposite to the field direction.
(A)
H
H-O
(B)
Atomic dipole configuration with and
without an external magnetic field for a
paramagnetic material.
(B)
Figure by MIT OCW.
Magnetic Units and Conversion Factors for the SI and cgs-emu Systems
SI Units
Quantity
Symbol
Derived
Primary
cgs-emu Unit
Conversion
Magnetic Induction
(Flux Density)
B
tesla (Wb/m2)*
kg/s-C
gauss
1 Wb/m2 = 104 gauss
Magnetic Field
Strength
H
amp-turn/m
C/m-s
oersted
1 amp-turn/m = 4π x
10-3 oersted
Magnetization
M (SI)
I (cgs-emu)
amp-turn/m
C/m-s
maxwell/cm2
Permeability of
a Vacuum
µ0
henry/m**
kg-m/C2
Unitless (emu)
4π x 10-7 henry/m
= 1 emu
µr (SI)
µ' (cgs-emu)
Unitless
Unitless
Unitless
µr = µ'
χm (SI)
χ'm (cgs-emu)
Unitless
Unitless
Unitless
χm = 4πχ'm
Relative Permeability
Susceptibility
1 amp-turn/m = 10-3
maxwell/cm2
*Units of the weber (Wb) are volt-seconds.
**Units of the henry are webers per ampere.
Figure by MIT OCW.
Magnetic materials in materials science & engineering
Room-Temperature Magnetic Susceptibilities for
Diamagnetic and Paramagnetic Materials
Paramagnetics
Diamagnetics
Material
Figure by MIT OCW.
Susceptibility χn
(volume)
(SI units)
Material
Susceptibility
χn (volume)
(SI units)
Aluminum oxide
-1.81 x 10-5
Aluminum
2.07 x 10-5
Copper
-0.96 x 10-5
Chromium
3.13 x 10-4
Chromium chloride
1.51 x 10-3
Gold
-3.44 x
Mercury
-2.85 x 10-5
Manganese sulfate
3.70 x 10-3
Silicon
-0.41 x 10-5
Molybdenum
1.19 x 10-4
Silver
-2.38 x 10-5
Sodium
8.48 x 10-6
Sodium chloride
-1.41 x 10-5
Titanium
1.81 x 10-4
Zinc
-1.56 x 10-5
Zirconium
1.09 x 10-4
10-5
Courtesy of Professor Robert O'Handley. Used with permission.