Magnetic resistivity in SrRuO 3 and the ferromagnetic phase transition

We measured the resistivity of the itinerant ferromagnet SrRuO3 as a function of temperature (120K<T<180 K) and magnetic field (0<H<10 kOe) in the vicinity of the ferromagnetic phase transition (Tc∼150 K). We find that the magnetic resistivity ρm is related to the magnetization M by ρm(M)=ρm(0)−aM2 over a wide range of M. From the analysis of the resistivity data we determine the critical parameters of the phase transition β=0.34±0.02, γ=1.14±0.07 below Tc, γ=1.17±0.14 above Tc, C+/C−∼4. Here β and γ are the critical exponents of the spontaneous magnetization and the susceptibility, respectively, and C+/C− is the amplitude ratio of the susceptibility. Our results are supported by a collapse of the magnetoresistance data on a single curve when an approriate scaling function is used.