Influence of carbon on intraband scattering in Mg(B_1-xC_x)₂

¹  Institute of Low Temperature and Structure Research, Polish Academy of Sciences - P.O. Box 1410, 50-950 Wrocław, Poland, EU
²  Laboratory for Solid State Physics, ETH Zurich - 8093 Zurich, Switzerland

Corresponding author: M.Matusiak@int.pan.wroc.pl

Received: 3 December 2009
Accepted: 19 April 2010

Abstract

We report data on the Hall coefficient (R_H) of the carbon-substituted Mg(B_1-xC_x)₂ single crystals with x in the range from 0 to 0.1. The temperature dependences of R_H obtained for the substituted crystals differ systematically at low temperatures, but all of them converge to the value of 1.8 × 10^-10 m³C^-1 at room temperature. The R_H(T) data together with results of the thermoelectric power and electrical-resistivity measurements are interpreted within a quasi-classical transport approach, where the presence of four different conducting sheets is considered. The main influence of the carbon substitution on the transport properties in the normal state is associated with enhanced scattering rates rather than modified concentration of charge carriers. Presumably the carbon substitution increases the electron-impurity scattering mainly in the π-band.