Specific heat of U1−xYxRu2Si2; 0⩽x⩽0.5: search for a hidden order

Abstract Specific heat for U 1− x Y x Ru 2 Si 2 alloys, with 0⩽ x ⩽0.5, is reported. All studied alloys showed an anomaly at a temperature T m . T m is rapidly reduced with x for small x (⩽0.02), increases for x =0.05, and is only weakly x -dependent for larger concentrations. This and other low temperature characteristics are consistent with the existence of two-ordered phases.