Evidence for current-induced phase coexistence in Ca 2 RuO 4 and its influence on magnetic order

K. Jenni (1) , F. Wirth (1) , K. Dietrich (1) , L. Berger (1) , Yvan Sidis (2) , S. Kunkemöller (1) , C. Grams (1) , D. Khomskii (1) , J. Hemberger (1) , M. Braden (1)

1 II. Physikalisches Institut [Köln]
2 NFMQ - LLB - Nouvelles frontières dans les matériaux quantiques

Combining quasistatic and time-resolved transport measurements with X-ray and neutron diffrac-tion experiments we study the non-equilibrium 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 ∼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.

Domaines: Physique [physics]; Matière Condensée [cond-mat]

K. Jenni, F. Wirth, K. Dietrich, L. Berger, Yvan Sidis, et al.. Evidence for current-induced phase coexistence in Ca 2 RuO 4 and its influence on magnetic order. Physical Review Materials, 2020, 4 (8), ⟨10.1103/PhysRevMaterials.4.085001⟩. ⟨hal-02989952⟩