Electronic and thermal properties of Ti3Al(C-0.5,N-0.5)(2), Ti2Al(C-0.5,N-0.5) and Ti2AlN

In this paper we report on the electronic, magnetotransport, thermoelectric, and thermal properties of Ti3Al(C-0.5,N-0.5)(2), Ti2Al(C-0.5,N-0.5), and Ti2AlN. The electrical conductivities, Hall coefficients, and magnetoresistances are analyzed within a two-band framework and compared with the end members, Ti2AlC and Ti3AlC2. The analysis shows that all compounds are compensated conductors with hole and electron carrier densities of about 1.5x10(27) m(-3). The room temperature thermal conductivities of the carbonitrides are both over approximate to 50 W/mK, with the phonon contribution of Ti3Al(C-0.5,N-0.5)(2) particularly large at over 35 W/mK. The low-temperature specific heat of Ti3Al(C-0.5,N-0.5)(2) and Ti2Al(C-0.5,N-0.5) yield Debye temperatures of 685 and 724 K, respectively, comparable to those of the end members. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2979326]