Hopping regime

Fig. 11.18. Temperature dependence of the metallic conductance of the infinite cluster GidT) deduced from the difference between the experimental conductance and that corresponding to the hopping regime (see text) 6 K (7 ) = [Gexp(r) — Gho] T)]. The dashed lines are guides for eyes [85],...

Figure 53. Frequency-dependent conductivity of RbAg4ls at 129 K. (More precisely a- represents the real part of the complex conductivity.) As the continuous line shows, the jump-relaxation model in Ref.278-280 can well describe the behavior in the hopping regime.278 Reprinted from K. Funke, Prog. Solid St Chem., 22 (1993) 111-195. Copyright 1993 with permission from Elsevier.

At low temperatures, the small-polaron moves by Bloch-type band motion, while at elevated temperatures it moves by thermally activated hopping mechanism. Holstein (1959), Friedman and Holstein (1963), Friedman (1964) performed the theoretical calculations of small-polaron motion and showed that the temperature dependencies of the small-polaron mobility in the two regimes are different. In the high-temperature hopping regime, the electrical conductivity is thermally activated and it increases with increasing temperature. As shown by Naik and Tien (1978), its temperature dependence is characterized by the following equation... 

Figure 12. The PT rate, r in BA as a function of temperature at a pressure of 2 kbar. Solid squares ( ) are data points from QENS and open circles (O) are values derived from NMR Tj measurements. The data asymptotically approach the incoherent quantum-tunneling regime at low temperature and the classical barrier-hopping regime at high temperature. The dashed and solid lines are different fits to theory (see text). (Adapted from Horsewill et al. [158].)...

In this chapter, we focus on the hopping regime and start with a primer on electron-transfer theory in Section 1.1.2. This section will underline the three major parameters that enter the expression of the electron-transfer rate reorganization energy, electronic coupling, and driving force. We then discuss some examples of the impact of chemical structure and packing mode on these parameters. Section... 

Xiang L, PalmaJL, Bruot C, Mujica V, Ratner MA, Tao N. Intermediate mnnePing— hopping regime in DNA charge transport. Nat Chem. 2015 7 221-226. 

---