UC Irvine

Measurements of electrical resistivity at applied pressures up to 55 kbar have been carried out on single crystals of the ferromagnet CeNiSb 3 revealing a complex magnetic phase diagram. The ferromagnetism at ambient pressure at T c=6 K first increases with pressure up to 25 kbar, then decreases slightly for P > 25 kbar. In the pressure range 35 kbar≤P≤55 kbar, a second anomaly in the resistivity is found at T M2, below another higher temperature magnetic phase that is conjectured to be different than the ferromagnetism present at lower pressure. Changes in the physical properties such as the residual resistivity, and low temperature maximum in ρ mag(T) suggest a modification of the electronic structure where the two magnetic phases coexist with one another above 35 kbar. The critical pressure for the suppression of the lower temperature phase is estimated to be P cmag2≃55 kbar, while the increase of both the T 2 coefficient of the electrical resistivity A and residual resistivity ρ 0 is suggestive of a quantum critical point associated with the higher temperature magnetic phase at P cmag1∼60 kbar. ©2005 The American Physical Society.