Electrical transport, thermal transport, and elastic properties of M2AlC (M=Ti, Cr, Nb, and V)

Abstract

In this paper we report on a systematic investigation, in the 5to300K temperature regime, of the electronic, magnetotransport, thermoelectric, thermal, and elastic properties of four M2AlC phases: Ti2AlC, V2AlC, Cr2AlC, and Nb2AlC. The electrical conductivity, Hall coefficient, and magnetoresistances are analyzed within a two-band framework assuming a temperature-independent charge carrier concentration. As with other MAX-phase materials, these ternaries are nearly compensated, viz. the densities and mobilities of electrons and holes are almost equal. There is little correlation between the Seebeck and Hall coefficients. With Young's and shear moduli in the 270GPa and 120GPa range, respectively, the phases studied herein are reasonably stiff. With room temperature thermal conductivities in the 25WmK range (45WmK for V2AlC) they are also good thermal conductors. © 2005 The American Physical Society.