Antiferromagnetism of β-Ce under hydrostatic pressure

The magnetic properties of β-Ce at low temperature have been studied through ac susceptibility measurements under hydrostatic He-gas pressure up to 4.5 kbar. The Néel temperature, TN = 12.7 K at 58 bar, initially increases with pressure at the rate dTN/dP = +0.32 ± 0.05 K/kbar. After releasing pressure from 4.5 to 0.06 kbar at 40 K, the magnetic susceptibility anomaly associated with the antiferromagnetic transition is markedly reduced. Surprisingly, TN also shifts from 12.7 to 14 K. Both effects likely arise from an irreversible β → α transition under pressure.