Electrical and thermal properties of single crystalline Mo5X3 (X=Si, B, C) and related transition metal 5-3 silicides

Thermal properties of a reaction hot pressed Mo≤5Si3C≤1 ceramic

“…4. As expected for a metallic conductor, the electrical resistivity increased with temperature, from 118 mU cm at room temperature to 138 mU cm at 600 C. Measured values were w10 mU cm higher than those reported for single crystal Mo 4.8 Si 3 C 0.6 [7]. The difference with respect to single crystal values was attributed to grain boundary electron scattering.…”

“…At the minimum temperature it was measured, À160 C, the thermal diffusivity was 5.3 mm 2 /s. The maximum thermal diffusivity was 8.5 mm 2 /s at w1100 C. Diffusivity measured by Ito et al for single crystal Mo 5 Si 3 C in the [11] ½2; 0 was w3.1 mm 2 /s [7]. The thermal diffusivity has not been measured in the [0001] for single crystals.…”

“…Reported single crystal resistivities vary <5% between [110] and [001] [7]. The small anisotropy was ignored for this study and resistivity was only measured perpendicular to the hot pressed direction.…”

“…Electrical properties were measured for single crystals. Reported resistivities vary <5% between [110] and [001] and are w110 mU cm at room temperature [7]. Mechanical properties of polycrystalline samples have been investigated despite difficulty in producing phase pure samples.…”

“…Room temperature thermal conductivity has been calculated for single crystal samples in the [11] ½2; 0 direction of 8.5 W/m K [7] and thermal expansion (CTE) has been measured from RT to 800 C for the c-and a-axes [1] to increase from 9.2 to 16 and 4.8 to 8.0 ppm/ C, respectively.…”