Pressure effects in the itinerant antiferromagnetic metal TiAu

We report the pressure dependence of the Néel temperature TN up to P≈27 GPa for the recently discovered itinerant antiferromagnet (IAFM) TiAu. The TN(P) phase boundary exhibits unconventional behavior in which the Néel temperature is enhanced from TN≈33 K at ambient pressure to a maximum of TN≈35 K occurring at P≈5.5 GPa. Upon a further increase in pressure, TN is monotonically suppressed to ∼22 K at P≈27 GPa. We also find a crossover in the temperature dependence of the electrical resistivity ρ in the antiferromagnetic (AFM) phase that is coincident with the peak in TN(P), such that the temperature dependence of ρ=ρ0+AnTn changes from n≈3 during the enhancement of TN to n≈2 during the suppression of TN. Based on an extrapolation of the TN(P) data to a possible pressure-induced quantum critical point, we estimate the critical pressure to be Pc≈45 GPa.