Effect of pressure on metamagnetic Sr₃Ru₂O₇

We have studied the effect of hydrostatic pressure on the metamagnetic transition in Sr3Ru2O7. For B perpendicular to c, a peak in the magnetoresistance near the metamagnetic field B-M approximate to 5 T suggests scattering due to strong fluctuations near a quantum critical point. On applying pressure, B-M increases linearly, extrapolating to B-M = 0 at a pressure p(c) approximate to -14 kbar. Scaling behaviour of the magnetoresistance with pressure suggests that the nature of the spin fluctuations is invariant under pressure. This demonstrates that spin fluctuations associated with the metamagnetism dominate the physics over a large region of pressure, temperature and field. (C) 2002 Elsevier Science B.V. All rights reserved.