In-depth study of the H-T phase diagram of Sr4Ru3O10 by magnetization experiments

We present magnetization measurements on Sr4Ru3O10 as a function of temperature and magnetic field applied perpendicular to the magnetic easy c-axis inside the ferromagnetic phase. Peculiar metamagnetism evolves in Sr4Ru3O10 below the ferromagnetic transition TC as a double step in the magnetization at two critical fields Hc1 and Hc2. We map the H-T phase diagram with special focus on the temperature range 50. K <=T<=TC. We find that the critical field Hc1(T) connects the field and temperature axes of the phase diagram, whereas the Hc2 boundary starts at 2.8. T for the lowest temperatures and ends in a critical endpoint at (1. T; 80. K). We conclude from the temperature dependence of the ratio Hc1Hc2(T) that the double metamagnetic transition is an intrinsic effect of the material and it is not caused by sample stacking faults such as twinning or partial in-plane rotation between layers.