Nordheim-Gorter rule

The Nordheim-Gorter rule is given for non-magnetic RI compounds by... 

In the following sections the basic concepts of the transport theories within the scope of the Boltzmann formalism are described. In the succeeding discussion the validity and the applicability of the Matthiessen and the Nordheim-Gorter rule are considered. A description of transport phenomena (electrical and thermal resistivity, thermopower) without an external magnetic field is given in sect. 2.3. There, the influence of the various scattering mechanisms on the temperature dependence of the electrical and the thermal resistivity as well as on the thermopower will be briefly discussed. 

Splitting of the transport coefficients into the various contributions is, under certain circumstances, possible using the sum rules , although these rules can only be applied in rather limited cases. In the following we will discuss these sum rules, which are the Matthiessen rule, the Kohler rule and the Nordheim-Gorter rule. 

The Kohler rule or the Nordheim-Gorter rule can be used in the same way as the Matthiessen rule to separate the different contributions to the total thermopower S. ... 

For the analysis of these data Gratz and Nowotny (1985) used the Nordheim-Gorter rule, which is, in the case of a non-magnetic compound like YAI2, given by S T) = (pJp)Sq + (p Jp)S. The temperature variation of p and,.and the value of po re taken from the resistivity measurements. A calculation ofSo andSp within the scope of the linearized Boltzmann equation revealed that Sq is linear in... 

In the Nordheim-Gorter rule (eq. (35)) the spin-dependent scattering processes of the conduction electrons are described by the third term ((Pmag/p)Smag)- According to the discussion in sect. 2.3 (see eq. (49)), > T ) = is proportional to T (if... 

Equation 23 goes by the name, Gorter-Nordheim rule it indicates that a plot of e vs. cr( = l/p) will be linear. On the other hand, if one has a single scattering mechanism and two groups of carriers (two bands), then the conductivities rather than resistivities are added a = band model the thermopower is ... 

---