Charge carrier transport with weak coupling in BaBiO3

We have presented the electrical conductivity for the semiconducting BaBiO3 as a function of temperature. We have observed that the conductivity is nonactivated and that the variable range hopping and the small polaron hopping cannot dominate the charge transport process in BaBiO3 like other semiconductors. On the contrary, we have observed that the logarithmic conductivity is proportional to T-p, where the exponent p is independent of temperature. We have shown that the charge transport process occurs by the multiphonon assisted hopping of the charge carriers that interact weakly with phonons. (C) 1999 Elsevier Science Ltd. All rights reserved.