Multiphonon hopping transport in Bi2CuO4 single crystal

The d.c. electrical conductivity along c- and a, b-axes for the Bi2CuO4 single crystal has been studied as a function of temperature for the first time. We have observed that the variable range hopping mechanism cannot dominate the charge transport process in Bi2CuO4, unlike the rare earth cuprate La2CuO4. On the contrary, we have observed that the temperature dependence of the d.c. conductivity a can be described by sigma similar to T-p, where the exponent p is dependent on measurement axes and on the temperature range. We have interpreted the results in the framework of the multiphonon assisted hopping theory with a weak electron-phonon coupling. (C) 1998 Elsevier Science Ltd. All rights reserved.