Abstract
The general characteristics of Zintl compounds are discussed with particular emphasis on the use of these materials in thermoelectric devices for the conversion of heat into electricity. In addition to thermoelectric applications, many of these Zintl phases also have unusual correlated ground states. The tetragonal compound Yb14MnSb11 is a good example. This compound exhibits excellent thermoelectric properties at high temperatures and at low temperatures is believed to be a rare example of an underscreened Kondo ferromagnet. In the ferromagnetic state the anomalous Hall effect (AHE) data from Yb14MnSb11 is highly anisotropic, and reflects the competition between a ferromagnetic ground state and Kondo screening. In one direction (H//a, I//c), the AHE data are "normal", and dominated by intrinsic Berry phase physics. In another orientation (H//c, I//a), Kondo skew scattering appears to dominate.
