Y substitution effect to the dense Kondo behavior of amorphous Ce–Mn alloys

Abstract

We have measured the specific heat and the resistivity on sputtered amorphous (a-) Ce 80− x Y x Mn 20 alloys ( x = 10 , 20, 30, 50 and 70), substituted by Y for dense Kondo a-Ce–Mn alloy. The electronic specific heat coefficient γ shows the large value ( γ = 133 mJ / mol K 2 ) at x = 10 and decreases with increase of the Y concentration linearly. The resistivity at low temperature shows the T 2 dependence and the large coefficient A at x = 10 , 20. However, the T 2 dependence was not observed for x⩾30. Thus, a-Ce 80− x Y x Mn 20 for x⩽20 is also the dense Kondo system. We made Kadowaki–Woods plot from A and γ of a-Ce–Mn and a-Ce-Y-Mn alloys. The ratio of A/ γ 2 for a-Ce-Y-Mn is much larger than the value of a-Ce–Mn alloy.