Galvanomagnetic properties of CdTe below and above the melting point

Temperature dependence of conductivity sigma and Hall coefficient R-H is measured by DC and AC methods at temperatures between 600-1180 degreesC. Two experimental approaches are used.(1) Galvanomagnetic measurements at defined temperature and Cd or Te pressure are performed in solid samples in the whole field of stability of solid in the pressure-temperature (P-T) diagram.(2) Galvanomagnetic measurements define temperature both in solid and in liquid phase. The typical semiconducting character of sigma and 1/ \ eR(H)\ ,when both parameters increase with temperature, is observed also in the liquid. The negative sign of R-H is observed above 600 degreesC within the whole region of stability of solid, both at Cd and at Te saturation, and R-H < 0 both in solid and liquid. 1/<vertical bar>eR(H)\ reaches 5 x 10(19) cm(-3) at 1180 degreesC and the corresponding Hall mobility is 20 cm(2)/Vs. Three slopes characterize the temperature dependence of a 0.7 eV in the solid CdTe below the melting point 1092 degreesC and 4.6 eV in the liquid phase at 1092 degreesC < T < 1160 degreesC. Above 1160 degreesC, conductivity increases moderately with the slope 0.8 eV. The experimental data for solid CdTe are evaluated by a theoretical model, including electrons from both the central minimum (T-point) and four satellite minima (L-point) of the Brillouin zone. The ab initio results fit our experimental data after small modifications very well.