2016/03/29 by Hao Zheng, H. Zheng, J. Terzic +11
Chemistry · Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Atomic physics #Chemistry #Condensed matter physics #Crystal structure #Crystallography #Electrical resistivity and conductivity #Ground state #Isostructural #Magnetic and transport properties of perovskites and related materials #Materials science #Orthorhombic crystal system #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.93.235157
published as Phys. Rev. B 93, 235157 (2016) · 5 figures
arxiv created 2016/03/29 · openalex created_date 2016/06/24 · openalex publication_date 2016/06/27 · arxiv updated 2016/07/06 · openalex updated_date 2026/08/06
The orthorhombic perovskite SrIrO3 is a semimetal, an intriguing exception in iridates where the strong spin-orbit interaction coupled with electron correlations tends to impose an insulating state. We report results of our investigation of bulk single-crystal Sr0.94Ir0.78O2.68 or Ir-deficient, orthorhombic perovskite SrIrO3. It retains the same crystal structure as stoichiometric SrIrO3 but exhibits a sharp, simultaneous antiferromagnetic (AFM) and metal-insulator (MI) transition occurring in the basal-plane resistivity at 185 K. Above it, the basal-plane resistivity features an extended regime of almost linear temperature dependence up to 800 K but the strong electronic anisotropy renders an insulating behavior in the out-of-plane resistivity. The Hall resistivity undergoes an abrupt sign change and grows below 40 K, which along with the Sommerfeld constant of 20\phantom\rule0.16em0exmJ/mol\phantom\rule0.16em0exK2 suggests a multiband effect. All results including our first-principles calculations underscore a delicacy of the paramagnetic, metallic state in SrIrO3 that is in close proximity to an AFM insulating state. The contrasting ground states in isostructural Sr0.94Ir0.78O2.68 and SrIrO3 illustrate a critical role of lattice distortions and Ir deficiency in rebalancing the ground state in the iridates. Finally, the concurrent AFM and MI transitions reveal a direct correlation between the magnetic transition and formation of an activation gap in the iridate, which is conspicuously absent in Sr2IrO4.