Competition of antiferromagnetism and superconductivity in Cr-Ru alloys

We report experimental results from systematic studies on the interplay between the antiferromagnetic spin density wave and the superconductivity in Cr 1- x Ru x alloys. Unlike previous reports, the two phases never coexist and the phase transition as the function of x appears to be of the first order. This clean evidence leads to a conclusion that the antiferromagnetic SDW is stabilized by the excitonic phase formation competing with the Bose condensation of the superconductivity in Cr 1- x Ru x alloys.