Related papers: The Chemical Instability of Na2IrO3 in Air
We report the successful synthesis of single-crystals of the layered iridate, (Na$_{1-x}$Li$_{x}$)$_2$IrO$_3$, $0\leq x \leq 0.9$, and a thorough study of its structural, magnetic, thermal and transport properties. The new compound allows a…
The synthesis, structure, and elementary magnetic and electronic properties are reported for layered compounds of the type Na3-xMIr2O6 and Na3-xM2IrO6, where M is a transition metal from the 3d series (M=Zn, Cu, Ni, Co, Fe and Mn). The…
The honeycomb lattice iridate Na$_2$IrO$_3$ shows frustrated magnetism and can potentially display Kitaev-like exchange interactions. Recently, it was shown that the electronic properties of the surface of crystalline Na$_2$IrO$_3$ can be…
We investigated the crystal structure, magnetic behavior, and optical properties of the layered honeycomb compound Na2Cu2TeO6. X-ray and neutron diffraction confirmed a monoclinic structure, with Cu ions arranged in dimerized chains.…
The synthesis, structure, and basic magnetic properties of Na2Co2TeO6 and Na3Co2SbO6 are reported. The crystal structures were determined by neutron powder diffraction. Na2Co2TeO6 has a two-layer hexagonal structure (space group P6322)…
We have synthesized single crystals of Na$_2$(Ir$_{1-x}$Ti$_x$)O$_3$ and polycrystals of Li$_2$(Ir$_{1-x}$Ti$_x$)O$_3$ and studied the effect of magnetic depletion on the magnetic properties by measurements of the magnetic susceptibility,…
The structural and magnetic properties of a new series of iridium-based honeycomb lattices with the formula Na3-delta(Na1-xMgx)Ir2O6 (x = 0 to 1) are reported. As x and delta are increased, the honeycomb lattice contracts and the strength…
Transition metal oxides with 4d or 5d metals are of great interest due to the competing interactions, of the Coulomb repulsion and the itineracy of the d-electrons, opening a possibility of building new quantum ground states. Particularly…
We report the structures and physical properties of two new iridates, NaIrO$_3$ and Sr$_3$CaIr$_2$O$_9$, both of which contain continuous two-dimensional honeycomb connectivity. NaIrO3 is produced by room temperature oxidative…
We have investigated experimentally and theoretically the series (Na$_{1-x}$Li$_{x}$)$_{2}$IrO$_{3}$. Contrary to what has been believed so far, only for $x\leq0.25$ the system forms uniform solid solutions. For larger Li content, as…
We demonstrate that the surface of the honeycomb lattice iridate Na$_2$IrO$_3$ is extremely tunable by plasma etching. We have succeeded in turning the surface of Na$_2$IrO$_3$ metallic by Ar plasma etching which leads to the removal of Na…
We have studied the magnetic properties of Na$_2$Co$_2$TeO$_6$, which features a honeycomb lattice of magnetic Co$^{2+}$ ions, through macroscopic characterization and neutron diffraction on a powder sample. We have shown that this material…
The structural properties of Na2RuO3 under pressure are studied using density functional theory within the generalized gradient approximation (GGA). We found that one may expect a structural transition at ~ 3 GPa. This structure at the…
A new honeycomb lattice iridate (La,Na)IrO$_3$ ($\approx$ LaNaIr$_2$O$_6$) is successfully synthesized from the spin-orbit coupled Mott insulator Na$_2$IrO$_3$ by replacing the interlayer Na$^+$ ions with La$^{3+}$ ions. (La,Na)IrO$_3$…
We report the decomposition of La2-xSrxCuO4 into La2O3 and Cu nanoparticles in ultra-high vacuum, observed by in-situ heating experiments in a transmission electron microscope (TEM). The analysis of electron diffraction data reveals that…
We report a detailed study of de-intercalation of Na from the compound NaxCoO2-d using an electrochemical technique. We find evidence for stable phases with Na contents near the fractions ~1/3, 1/2, 5/8, 2/3, and 3/4. Details regarding the…
We report the structure, magnetic, and thermal property measurements on single crystalline and polycrystalline samples of Ru substituted honeycomb lattice iridate Na$_2$Ir$_x$Ru$_{1-x}$O$_3$ (x = 0, 0.05, 0.1, 0.15, 0.2, 0.3, 0.5). The…
We report equilibrium and nonequilibrium optical measurements on the recently synthesized "harmonic" honeycomb iridate \gamma-Li$_2$IrO$_3$ (LIO), as well as the layered honeycomb iridate Na$_2$IrO$_3$ (NIO). Using Fourier transform…
The sodium reordering in NaxCoO2 in the vicinity of room temperature is rationalized at high x in terms of phase transitions between square and striped phases. A striking hexagon-of-hexagons diffraction pattern observed for x=0.78 can be…
High-pressure powder x-ray diffraction experiments have revealed that sodium and gold react at room temperature and form new Na-Au intermetallic compounds under high pressure. We have identified four intermetallic phases up to 60 GPa. The…