# Residual Resistivity and Defects

| Shown here are measured curves of the low temperature resistivity of Na with different defect concentrations
|  | The resistivity is constant for very small temperatures.
|  | In the "bend" it shows T 5 characteristics.
|  | For most of the temperature range it is proportional to T.
| Defects clearly do increase the residual resistance (the upper two curves are for Na with defects, the lower one for rather perfect Na); the effect can be much large in other metals or for larger defect densities.

With frame

2.2.1 Conductors

Specific Resistivity as a Function of Temperature

© H. Föll (Advanced Materials B, part 1 - script)