Evolution of the coherent quasi-particle polarization in the ordered state of the heavy fermion compound Ce(Ru0.9Rh0.1)2(Si1-yGey)2

Electrical resistivity measurements have been made to study the response of the magnetic order of the heavy fermion compound Ce(Ru0.9Rh0.1)2(Si1-yGey)2 to chemical pressure. In the Ge-concentration range of y<0.2, the resistivity shows a sharp upturn anomaly at TN due to a gap opening on the Fermi surface. On the other hand, in the higher Ge concentration region, the resistivity shows a downturn anomaly at TN. This shift of the type of the anomaly at TN indicates that the total ordered magnetization starts involving, with decreasing y, coherent quasi-particle component at y=0.2