  It has been shown that the observed correlation between the resistivity
$\rho$ of high-resistive metallic alloys and the sign of the temperature
derivative $d\rho/dT$ can be explained by taking into account the weak
localization. This correlation is known as Mooij rule: the derivative
$d\rho/dT$ is negative for alloys with resistivity in the range of
$300\div150\,\mu\Omega\cdot$cm, which corresponds to the electron mean free
path about the interatomic distance; however, this derivative is positive for
alloys with lower resistivity.
