Effect of non-magnetic dilution in

We report the evolution of the magnetic state in Ba2CoTeO6 with magnetic Co2+ substituted by non-magnetic Zn2+. Ba2CoTeO6, a strongly frustrated antiferromagnet which consists of two highly frustrated subsystems, undergoes two antiferromagnetic transitions at TN1 ~ 12 K and TN2 ~ 3 K, respectively. The magnetization and specific heat measurements demonstrate that the antiferromagnetic transition at TN1 in the parent compound Ba2CoTeO6 is drastically suppressed with Zn/Co substitution. On the other hand, with the increasing of Zn doping level x, the antiferromagnetic ordering below TN2 in Ba2CoTeO6 firstly becomes a spin glass state, and eventually transforms into a spin disordered state at higher Zn concentration x = 0.6. Our results indicate that magnetic site dilution by Zn/Co substitution is an effective approach to induce the novel disordered state in Ba2CoTeO6.