Magnetoresistance of highly oriented graphite at 77K and 4.2K

Author:
Publisher website
Google Scholar
Abstract
Transverse magnetoresistance is measured at magnetic fields up to 6.5 T at temperatures of 77K and 4.2K for highly oriented graphites; four samples of kish graphite with different crystallinity. The effect of the structural perfection of graphite on the field dependence of the exponent n in he magnetoresistance Delta rho / rho 0 against the magnetic field B relationship ( Delta rho / rho 0 varies as Bn) is examined. It is found that the relationship varies systematically with structural perfection. A minimum of n occurs in the low-field region for all samples at 77K and 4.2K. The curve of the exponent versus field is calculated on the basis of a multiple-carrier group model within the framework of Slonczewski-Wiess-McClure band model with the energy band parameter gamma 3=0. Good agreement between the calculated and experimental curves is obtained. The minimum of n can be attributed to the market dependence of the effective mass of carriers on k2 along the Brillouin zone edges.

This publication has 17 references indexed in Scilit: