Suppression of the resistivity anomaly and corresponding thermopower behavior in the pentatelluride system by the addition of Sb:Hf1-XZrXTe5-YSbY -: art. no. 121104

The electrical resistivity rho and the thermopower alpha of the transition-metal pentatelluride system Hf1-xZrxTe5-YSbY have been measured over a broad range of temperature, 10 K< T< 300 K. The systematic Sb doping of these materials has been performed over a range from 0<0.75, where Y is the nominal Sb concentration. Both parent materials (HfTe5 and ZrTe5) exhibit an anomalous resistive peak, T-P approximate to 80 K for HfTe5 and T-P approximate to 145 K for ZrTe5. Each parent material displays a large positive (p-type) thermopower (alpha greater than or equal to + 125 muV/K) around room temperature, which undergoes a change to a large negative (n-type) thermopower (alpha less than or equal to - 125 muV/K) below the peak temperature. At a specific level of Sb doping the resistive anomaly is no longer evident and results in a semimetallic temperature dependence. In addition the thermopower monotonically decreases with temperature with no change in sign as in the parent materials. X-ray-diffraction data reveals that the pentatelluride structure is still preserved at all doping concentrations.