From Mott insulator to ferromagnetic metal: A pressure study of Ca2RuO4

We show that the pressure-temperature phase diagram of the Mott insulator Ca2RuO4 features a metal-insulator transition at 0.5 GPa: at 300 K from paramagnetic insulator to paramagnetic quasi-two-dimensional metal, and at Tless than or equal to12 K from antiferromagnetic insulator to ferromagnetic, highly anisotropic, three-dimensional metal. We compare the metallic state to that of the structurally related p-wave superconductor Sr2RuO4, and discuss the importance of structural distortions, which are expected to couple strongly to pressure.