Optical study of interactions in a d-electron kondo lattice with ferromagnetism -: art. no. 046401

We report on a comprehensive optical, transport, and thermodynamic study of the Zintl compound Yb14MnSb11, demonstrating that it is the first ferromagnetic Kondo lattice compound in the underscreened limit. We propose a scenario whereby the combination of Kondo and Jahn-Teller effects provides a consistent explanation of both transport and optical data.