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 T_C as a double step in the magnetization at two critical fields H_c1 and H_c2. We map the H−T phase diagram with special focus on the temperature range 50 K ≤T≤T_C. We find that the critical field H_c1(T) connects the field and temperature axes of the phase diagram, whereas the H_c2 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 [Formula presented](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.