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

We have measured the specific heat and the resistivity on sputtered amorphous (a-) Ce80-xYxMn20 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=133mJ/molK2) at x=10 and decreases with increase of the Y concentration linearly. The resistivity at low temperature shows the T2 dependence and the large coefficient A at x=10, 20. However, the T2 dependence was not observed for x>=30. Thus, a-Ce80-xYxMn20 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/γ2 for a-Ce-Y-Mn is much larger than the value of a-Ce-Mn alloy