Resistivity, exponential function of T
Presentation
This model defines a resistivity ρ as an exponential function of the temperature for an isotropic or anisotropic material.
Mathematical model
The resistivity is an exponential function of the temperature.
The corresponding mathematical formula is written:
            
         
where:
- T0 is the reference temperature [degree]
 - ρa + ρb is the resistivity of the material at T0 [Ω .m]
 - ρa is a constant quantity [Ω .m]
 - τ is the temperature constant (positive or negative) [degree-1]
 
The shape of ρ(T) curve is presented in the figure below.
            
         
Anisotropic material
For an anisotropic material, the exponential model consists of a group of three exponentials.