Temperature–Pressure Phase Diagram of Antiferromagnet CeAl

We studied the pressure effect up to 8 GPa on antiferromagnet CeAl by means of ac specific heat Cac, ac susceptibility χ′, and electrical resistivity ρ, and constructed temperature–pressure phase diagram. CeAl undergoes an antiferromagnetic (AFM) ordering at TN1 ∼ 10 K at ambient pressure, which is changed to three successive AFM transition temperatures \((T_{\text{N2}},T_{\text{N3}},T_{\text{N4}})\) above 1.7 GPa. AFM transition temperatures attain a maximum at 6.0 GPa and seem to vanish at P* = 7.5 GPa. A pressure induced phase, which emerges above 4.5 GPa, is also developed around P*. We analyzed low temperature resistivity in order to study quantum criticality around P*.