Magnetically ordered Kondo lattice in YbNi2Ge2at high pressure

We have studied the electrical resistivity of YbNi 2 Ge 2 under hydrostatic pressure up to 100 kbar. With increasing pressure the system is continuously tuned from an intermediate valence state at low pressure to a magnetically ordered Kondo lattice at high pressure. The critical pressure for the appearance of a magnetic ground state is near 50 kbar. Below P c the resistivity shows a T 2 dependence, characteristic of a Fermi liquid description at low temperatures. The coefficient of the T 2 term increases drastically on approaching P c . Above P c , the magnetic transition temperature T m increases linearly with pressure. The magnetoresistance at high pressure suggests the importance of ferromagnetic coupling.