Hall effect and charge carrier density in Eu(1-x)Ca(x)B6 (x = 0.2, 0.4, 0.6, and 0.9)

Abstract

Temperature and field dependent Hall resistivity rho(H)(T) has been measured for the single crystals of Eu1-xCaxB6 (x = 0.2; 0.4, 0.6, and 0.9). The effective charge carrier density n(eff)(T, H) and Hall mobility mu(H)(T) were derived from the rho(H)(T). A large variation in the n(eff)(T, H) for x = 0.2 and 0.4 compounds was found, while relatively small change for x = 0.6 and 0.9 compounds. Analysis of the mH; based on a small polaronic model, showed that the carrier transport is dominated by the activation of electrons in small polarons. This polaronic scenario of the transport is consistent with the variation of n(eff)(T, H). (C) 2003 Published by Elsevier B.V.