Kondo lattice behavior in the ordered dilute magnetic semiconductor Yb14-xLaxMnSb11 -: art. no. 205207

We report Hall, magnetic, heat capacity, and doping studies from single crystals of Yb14MnSb11 and Yb13.3La0.7MnSb11. These heavily doped semiconducting compounds are ferromagnetic below 53 and 39 K, respectively. The renormalization of the carrier mass from 2m(e) near room temperature to 20m(e) at 5 K, plus the magnetic evidence for partial screening of the Mn magnetic moments suggest that these compounds represent rare examples of an underscreened Kondo lattice with T-K approximate to 285 K.