Electrical, thermal, and elastic properties of the MAX-phase Ti2SC

We report on the electronic, thermal, and elastic properties of the layered ternary, Ti(2)SC. Resistivity, Hall effect, and magnetoresistance were measured as a function of temperature between 2 and 300 K and at fields up to 9 T. The Hall coefficient is negative and roughly temperature independent. The transport results were analyzed within a two-band framework, with electrons as the dominant charge carrier. The room-temperature thermal conductivity (approximate to 60 W/m K) is the highest of any MAX phase measured to date, with a substantial phonon contribution. The specific heat was measured from 2 to 300 K, yielding a Debye temperature of 765 K and in agreement with the Debye temperature of 745 K found from ultrasonic time-of-flight measurements. Young's, shear, and bulk moduli from the latter measurements were 290, 125, and 145 GPa, respectively. The calculated values of the lattice parameters (a=3.2051 angstrom and c=11.2636 angstrom), and Young's, shear, and bulk moduli (329, 138, and 179 GPa, respectively), based on the results of density functional theoretical simulations, compare favorably with measurements. (C) 2008 American Institute of Physics.