On the low temperature heat capacities of Ti2AlN and Ti2Al(N0.5C0.5)

In this paper, we report on the heat capacities, Cp, of bulk polycrystalline samples of Ti2AlN and solid solutions of Ti2Al(N0.5C0.5) in the 3–260 K temperature range. In spite of their different chemical compositions, the temperature dependencies of their Cp's are quite similar. The lattice contributions to Cp are analysed using the Debye and Einstein model approximations. The Debye temperatures for both compounds are reasonably high and fall in the 600–700 K range. At temperatures higher than 175 K, the Cp of the Ti2AlN0.5C0.5 sample is slightly larger than that of the end-members, Ti2AlN and Ti2AlC.