  We report a breakdown of the scaling of the antiferromagnetic transition
temperature T_N on chemical doping for Pt-doped CaFe2As2. The substitution of
Pt is ineffective in the reduction of antiferromagnetic ordering as well as in
inducing superconductivity in Ca(Fe1-xPtx)2As2. The Pt-doped CaFe2As2 that does
not exhibit superconductivity will, however, provide us an ideal opportunity to
elucidate the role of chemical doping in the occurrence of superconductivity in
iron-based materials.
