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Name |
Conductivity |
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Equation |
σ
=
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J
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E
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=
n
e
2
m
τ
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Definition of terms |
σ = conductivity, J = current density, E = electric field strength, n = number density of charge carriers, e = charge of charge carriers, m = mass of charge carriers, τ = mean time between collisions |
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Comments |
The first relationship is quoted for an isotropic material. For anisotropic materials,it is necessary to define J, σ and E as tensors.
The second relationship is valid only in the classical theory of conduction which assumes that the conduction electrons are free, and not bound to the metallic ions. |
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References
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Electricity and Magnetism , B I Bleaney, B Bleaney, OUP, 2nd edition, 1965 |
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