Dense Kondo states in Pd-Ce intermetallic compounds under high pressure

The electrical resistivity of Pd-Ce intermetallic compounds, Pd₅Ce₃, Pd₄Ce, has been measured under high pressures up to 10 GPa. It is found that the resistivity increases with the external pressure for all these intermetallics. The increase is due to the dense Kondo effect. Intermetallics with a higher concentration of Ce have a greater ratio of the resistivity-increase to pressure. However, a high-pressure X-ray diffraction experiment showed that the compressibility of the intermetallics is the same. These results suggest that the influence of pressure on the dense Kondo effect depends not only upon the Ce concentration but also on the local environment of Ce.