Giant magnetothermopower associated with large magnetoresistance in Ag2-δTe

We have probed the temperature and magnetic-field dependence of the thermopower and resistance of a p-type silver chalcogenide, Ag2-deltaTe. The application of a magnetic field causes not only a large magnetoresistance but also a giant magnetothermopower effect. The maximum change of thermopower is as high as 470 muV/K in a 7 T magnetic field. Both the magnetoresistance and the magnetothermopower show a pronounced peak and nearly linear behavior near the sign change of the thermopower. Bandcrossing and quantum confinement due to disorder appear to play key roles in the heightened response to field. (C) 2003 American Institute of Physics.