Decoupling of magnetism and electric transport in single-crystal (Sr1-xAx)2IrO4 (A = Ca or Ba)
arXiv:1712.05518 · doi:10.1088/1361-648X/aac23d
Abstract
We report a systematical structural, transport and magnetic study of Ca or Ba doped Sr2IrO4single crystals. Isoelectronically substituting Ca2+ (up to 15%) or Ba2+ (up to 4%) ion for the Sr2+ ion provides no additional charge carriers but effectively changes the lattice parameters in Sr2IrO4. In particular, 15% Ca doping considerably reduces the c-axis and the unit cell by nearly 0.45% and 1.00 %, respectively. These significant, anisotropic compressions in the lattice parameters conspicuously cause no change in the Néel temperature which remains at 240 K, but drastically reduces the electrical resistivity by up to five orders of magnitude or even precipitates a sharp insulator-to-metal transition at lower temperatures, i.e. the vanishing insulating state accompanies an unchanged Néel temperature in (Sr1-xAx)2IrO4. This observation brings to light an intriguing difference between chemical pressure and applied pressure, the latter of which does suppress the long-range magnetic order in Sr2IrO4. This difference reveals the importance of the Ir1-O2-Ir1 bond angle and homogenous volume compression in determining the magnetic ground state. All results, along with a comparison drawn with results of Tb and La doped Sr2IrO4, underscore that the magnetic transition plays a nonessential role in the formation of the charge gap in the spin-orbit-tuned iridate.
arXiv comment6 figures
References in corpus (21)
- Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
- Isospin Dynamics in Sr2IrO4 : Forging Links to Cuprate Superconductivity
- Twisted Hubbard Model for Sr2IrO4: Magnetism and Possible High Temperature Superconductivity
- The magnetic and crystal structures of Sr2IrO4: A neutron diffraction study
- Lattice-Driven Magnetoresistivity and Metal-Insulator Transition in Single-Layered Iridates
- Evidence of an odd-parity hidden order in a spin-orbit coupled correlated iridate
- Two-dimensional Heisenberg behavior of Jeff = 1/2 isospins in the paramagnetic state of spin-orbital Mott insulator Sr2IrO4
- Spin-orbit tuned metal-insulator transitions in single-crystal Sr2Ir1-xRhxO4 (0\leqx\leq1)
- The influence of electron-doping on the ground state of (Sr{1-x}La{x})2IrO4
- Dimensionality controlled Mott transition and correlation effects in single- and bi-layer perovskite iridates
- Local density of states study of a spin-orbit-coupling induced Mott insulator SrIrO
- Measurement of the internal magnetic field in the correlated iridates CaIrO, CaIrO, SrIrO and SrIrO
- Persistent non-metallic behavior in Sr2IrO4 and Sr3Ir2O7 at high pressures
- Decoupling of the Antiferromagnetic and Insulating States in Tb doped Sr2IrO4
- Evolution of competing magnetic order in the Jeff=1/2 insulating state of Sr2Ir1-xRuxO4
- From Jeff=1/2 insulator to p-wave superconductor in single-crystal Sr2Ir1-xRuxO4 (0 < x< 1)
- Pressure-Induced Insulating State in Ba1-xRExIrO3 (RE = Gd, Eu) Single Crystals
- Schwinger boson spin liquid states on square lattice
- Pressure dependence of the structure and electronic properties of Sr3Ir2O7
- Optical Signatures of Spin-Orbit Exciton in Bandwidth Controlled SrIrO Epitaxial Films via High-Concentration Ca and Ba Doping
- Structural evolution and electronic properties of (Sr1-xCax)2-yIrO4+z spin-orbit assisted insulators