Galvanomagnetic properties of CdTe below and above the melting point

Temperature dependence of conductivity sigma and Hall coefficient R-H is me asured by DC and AC methods at temperatures between 600-1180 degreesC. Two experimental approaches are used.(1) Galvanomagnetic measurements at define d temperature and Cd or Te pressure are performed in solid samples in the w hole field of stability of solid in the pressure-temperature (P-T) diagram. (2) Galvanomagnetic measurements define temperature both in solid and in li quid phase. The typical semiconducting character of sigma and 1/ \ eR(H)\ , when both parameters increase with temperature, is observed also in the liq uid. The negative sign of R-H is observed above 600 degreesC within the who le 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. Thr ee 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 a t 1092 degreesC < T < 1160 degreesC. Above 1160 degreesC, conductivity incr eases moderately with the slope 0.8 eV. The experimental data for solid CdT e are evaluated by a theoretical model, including electrons from both the c entral minimum (T-point) and four satellite minima (L-point) of the Brillou in zone. The ab initio results fit our experimental data after small modifi cations very well.