Antiferromagnetism and Valence Fluctuation of EuCd₁₁ at High Pressure

Abstract

We have measured the electrical resistance of EuCd 11 to study the T N and valence state at higher pressure up to 30 GPa. The T N increases with pressure up to 10 GPa, as same as the previous report. At pressure above 10 GPa, the R shows a kink structure and nearly quadratic temperature dependence at a lower temperature, which is different from the behavior of the antiferromagnetic ordering region. The peak temperature increases with pressure up to around 25 GPa, and for further pressurization, the R shows a negative logarithmic dependence in two different temperature regions. Kondo-like − log T and Fermi liquid T 2 dependences of R(T) are similar to that typically seen in the heavy-fermion system in which the characteristic energy scale Kondo temperature T K is enhanced by pressure.