High pressure study on uranium heavy fermion compounds with antiferromagnetic ground state

We have studied the high pressure effect on the antiferromagnetic ground states of uranium heavy fermion compounds. In this paper we show our high pressure studies on U₂Zn₁₇ by the electrical resistivity measurements. In U₂Zn₁₇, the Néel temperature T_N in U₂Zn₁₇ decreases slightly from 9.66 K at 1 bar to 9.33 K at 2.5 GPa, becomes almost pressure-independent up to 4.7 GPa, and starts to increase at the higher pressure region. We discuss the pressure dependences of the coefficient of T₂ term in the electrical resistivity A, an antiferromagnetic gap δ and a characteristic temperature T_ρmax. It is found that the effect of pressure on the electronic states in U₂Zn₁₇ is weak compared with the other heavy fermion compounds. The experimental results on UCu₅ is also discussed briefly.