Evidence For Current-Induced Phase Coexistence In Ca2ruo4 And Its Influence On Magnetic Order

Combining quasistatic and time-resolved transport measurements with x-ray and neutron diffraction experiments we study the nonequilibrium states that arise in pure and in Ti-substituted Ca2RuO4 under the application of current densities. Time-resolved studies of the current-induced switching find a slow conductance relaxation that can be identified with heating and a fast one that unambiguously proves an intrinsic mechanism. The current-induced phase transition leads to complex diffraction patterns. Separated Bragg reflections that can be associated with the metallic and insulating phases by their lattice parameters, indicate a real structure with phase coexistence that strongly varies with temperature and current strength. A third contribution with a c lattice constant in between those of metallic and insulating phases appears upon cooling. At low current densities, this additional phase appears below similar to 100 K and is accompanied by a suppression of the antiferromagnetic order that otherwise can coexist with current carrying states. A possible origin of the intermediate phase is discussed.