Stoichiometric Sr2IrO4 is a ferromagnetic J eff 1/2 Mott insulator driven by strong spin-orbit coupling. Introduction of very dilute oxygen vacancies into single-crystal Sr 2IrO4- with δ≤0.04 leads to significant changes in lattice parameters and an insulator-to-metal transition at TMI 105 K. The highly anisotropic electrical resistivity of the low-temperature metallic state for δ ≈ 0.04 exhibits anomalous properties characterized by non-Ohmic behavior and an abrupt current-induced transition in the resistivity at T*=52 K, which separates two regimes of resistive switching in the nonlinear I-V characteristics. The novel behavior illustrates an exotic ground state and constitutes a new paradigm for devices structures in which electrical resistivity is manipulated via low-level current densities ∼ 10 mA/cm2 (compared to higher spin-torque currents ∼ 10 7-108 A/cm2) or magnetic inductions ∼ 0.1-1.0 T.
|Journal||Journal of Applied Physics|
|State||Published - Apr 1 2011|
Bibliographical noteFunding Information:
G. C. is thankful to Dr. M. Whangbo and Dr. J. W. Brill for useful discussions. This work was supported by the NSF through Grants Nos. DMR-0552267, DMR-0856234, and EPS-0814194 (G.C.), and by DOE through Grants Nos. DE-FG02-97ER45653 (L.E.D.) and DE-FG02-98ER45707 (P.S.).
ASJC Scopus subject areas
- Physics and Astronomy (all)