Effect of Pressure on the Temperature Dependence of the Effective Thermal Conductivity of Gallium Antimonide with Different Degrees of Ordering

The results of experimental measurements of the temperature dependence of the effective thermal conductivity of various forms of gallium antimonide (single crystal, polycrystals) are analyzed. The thermal conductivity is measured by the absolute steady-state method in the temperature and pressure ranges 273–423 K and 0.1–350 MPa, respectively. For polycrystalline compounds, the temperature dependence of the effective thermal conductivity in the entire investigation range is shown to decrease with pressure, retaining a pronounced power-law character. The pressure dependences of both the relative effective thermal conductivity at a fixed temperature and the dependence of the relative change in the power-law coefficient of the temperature dependence within the experimental error could be approximated by two-parameter power functions. A description of the PT dependence of the effective thermal conductivity in the entire investigation range is proposed, for which the correlative relationship of the pressure components is found. The anomalous behavior of the temperature dependence of the thermal conductivity of a single-crystal GaSb sample with an increase in pressure is revealed, for which a significant increase in the absolute value of the power-law coefficient of the temperature dependence is observed up to ~1.5 at P = 330 MPa. The pressure dependences of the effective thermal conductivity demonstrate a significantly greater and nonlinear relative increase in the thermal conductivity compared to a single crystal, which indicates a large contribution to the effective thermal conductivity of the grain boundaries.