An unusual interplay among disorder, Kondo-effect and spin-glass   behavior in the Kondo lattices, Ce$_2$Au$_{1-x}$Co$_x$Si$_3$
  We report the results of magnetic measurements for the solid solution Ce$_2$Au$_{1-x}$Co$_x$Si$_3$. The results reveal that this solid solution is characterized by a magnetic phase diagram (plot of magnetic transition temperature versus $x$) unusual for Kondo lattices. In particular, the spin-glass freezing induced by disorder is observed only for the compositions at the weak coupling limit; as one approaches the quantum critical point by a gradual replacement of Au by Co, this disorder effect is surprisingly suppressed in favor of long range antiferro-magnetic ordering in contrast to expectations. This unusual interplay between disorder, spin-glass freezing and the Kondo-effect calls for further refinement of theories on competition between magnetism and the Kondo effect. 
Subham Majumdar, E.V. Sampathkumaran, St. Berger, M. Della Mea, H.   Michor, E. Bauer, M. Brando, J. Hemberger, A. Loidl