Magnetoresistance in n- and p-type Ag_2Te: Mechanisms and applications

We compare the large magnetoresistive response of slightly nonstoichiometric Ag_(2±δ)Te for a wide range of hole (p⩽8×10^(17)  cm^(−3)) and electron (n⩽4×10^(18)  cm^(−3))carrier densities. In the p-type material alone, a characteristic peak in the resistivity ρ(T,H) is dramatically enhanced and moves to higher temperature with increasing magnetic field, resulting in a high field (H∼5 T) magnetoresistance that is sizeable even at room temperature. By contrast, n-type specimens are geared for low-field (H<0.1 T) applications because of a striking linear field dependence of the magnetoresistance that appears to be restricted to the Ag-rich materials.