Double metamagnetic transition inSr4Ru3O10

Abstract

We report a magnetization study down to 1.7 K for the trilayered ruthenate ${\mathrm{Sr}}_{4}{\mathrm{Ru}}_{3}{\mathrm{O}}_{10}$ for magnetic fields applied within the $ab$ plane. Our measurements reveal that the metamagnetic jump appearing in the isothermal magnetization curves below ${T}_{M}=68$ K is actually composed of two consecutive metamagnetic transitions, where the increase in the magnetization due to the second transition is roughly one third of the overall metamagnetic jump. We show that the metamagnetic critical fields for these two transitions increase as the temperature decreases, and that their difference has a weak temperature dependence that opens up in the proximity of the critical region near ${T}_{M}$. We discuss the origin of this double metamagnetic transition being due to either the ordering of the Ru $4d$ magnetic moments in the two inequivalent crystallographic Ru sites or to the presence of two van Hove singularities in the near-Fermi-level density of states.