Electronic and thermal properties of Ti3Al(C0.5,N0.5)2, Ti2Al(C0.5,N0.5) and Ti2AlN

In this paper we report on the electronic, magnetotransport, thermoelectric, and thermal properties of Ti3Al(C0.5,N0.5)2, Ti2Al(C0.5,N0.5), 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 1.5×1027 m−3. The room temperature thermal conductivities of the carbonitrides are both over ≈50 W/mK, with the phonon contribution of Ti3Al(C0.5,N0.5)2 particularly large at over 35 W/mK. The low-temperature specific heat of Ti3Al(C0.5,N0.5)2 and Ti2Al(C0.5,N0.5) yield Debye temperatures of 685 and 724 K, respectively, comparable to those of the end members.