Evolution from the antiferromagnetic to the intermediate valence state in the Ce(Rh1-xCox)2Si2 system

The effects of substituting rhodium by cobalt in the tetragonal antiferromagnetic compound CeRh2Si2 are studied by X-ray investigation and magnetic, electrical and specific heat measurements. In the Ce(Rh1-xCox)2Si2 solid solution, a transition from a magnetically ordered state to an intermediate valence state appears when x is nearly equal to 0.135. An increase of the linear coefficient of the specific heat gamma is observed at this transition. For xNeel temperature decreases rapidly when x increases.