LaSr₃NiRuO₄H₄: A 4d Transition‐Metal Oxide–Hydride Containing Metal Hydride Sheets

Abstract

The synthesis of the first 4d transition metal oxide-hydride, LaSr NiRuO H , is prepared via topochemical anion exchange. Neutron diffraction data show that the hydride ions occupy the equatorial anion sites in the host lattice and as a result the Ru and Ni cations are located in a plane containing only hydride ligands, a unique structural feature with obvious parallels to the CuO sheets present in the superconducting cuprates. DFT calculations confirm the presence of S=1/2 Ni and S=0, Ru centers, but neutron diffraction and μSR data show no evidence for long-range magnetic order between the Ni centers down to 1.8 K. The observed weak inter-cation magnetic coupling can be attributed to poor overlap between Ni 3dz2 and H 1s in the super-exchange pathways.

Hole and Electron Doping of the 4d Transition‐Metal Oxyhydride LaSr3NiRuO4H4

“…Electrical transport measurements performed on cold‐pressed powder samples indicated the La x Sr 4− x NiRuO 4 H 4 phases are highly insulating, with all samples exhibiting resistivities greater than 1 MΩ cm at room temperature, and thus too resistive to measure temperature dependent data with our equipment. Magnetization data collected from La x Sr 4− x NiRuO 4 H 4 (0.5< x <1.4) samples indicated the presence of small amounts of a ferromagnetic impurity, consistent with ≈2 mole% elemental nickel, as reported previously for LaSr 3 NiRuO 4 H 4 . Therefore the “ferromagnetic subtraction” method previously used to characterize LaSr 3 NiRuO 4 H 4 was also employed for the other members of the La x Sr 4− x NiRuO 4 H 4 (0.5< x <1.4) series, as described in the supporting information.…”

“…Recently we reported the synthesis of LaSr 3 NiRuO 4 H 4 , the first oxyhydride to contain a 4d transition‐metal, which is prepared via hydride‐for‐oxide anion exchange from the all‐oxide phase LaSr 3 NiRuO 8 . LaSr 3 NiRuO 4 H 4 has a structure based on the n =1 Ruddlesden‐Popper structure of La 2 CuO 4 , in which the CuO 2 sheets have been replaced by (Ni/Ru)H 2 sheets, as shown in Figure a.…”

“…LaSr 3 NiRuO 4 H 4 has a structure based on the n =1 Ruddlesden‐Popper structure of La 2 CuO 4 , in which the CuO 2 sheets have been replaced by (Ni/Ru)H 2 sheets, as shown in Figure a. The calculated electronic structure of LaSr 3 NiRuO 4 H 4 shown in Figure b indicates that Ru 2+ adopts a low‐spin d 6 , diamagnetic configuration, while the single unpaired electron of Ni 1+ resides in a orbital which has only minimal overlap with the 1s orbital of the in‐plane hydride anion (Figure d). Thus it is no surprise that LaSr 3 NiRuO 4 H 4 is observed to be a simple paramagnet with a moment in excellent agreement with that expected for a spin‐only S= centre, and weak spin‐spin coupling ( θ =−18.6 K) and no indication of any magnetic order down to 2 K …”

Hole and Electron Doping of Topochemically Reduced Ni(I)/Ru(II) Insulating Ferromagnetic Oxides

“…SXRD data collected from La x Sr 4– x NiRuO 8 (0.6 < x < 1.4) samples could be indexed using body-centered tetragonal unit cells based on the reported structure of the x = 1 phase LaSr 3 NiRuO 8 . , Structural models based on the reported structure of LaSr 3 NiRuO 8 , with adjusted La/Sr ratios, were refined against the SXRD data to achieve good fits, indicating that single-phase samples had been prepared. Figure a shows a plot of the lattice parameters of La x Sr 4– x NiRuO 8 phases as a function of composition, with further details and plots of the diffraction data shown in the Supporting Information.…”

Two Faces of Hydrogen in Yttrium Hydroxyhydride: Y2H3O(OH) – a New Inorganic Chiral System with Hydridic and Protonic Hydrogens

“…Original synthesis routes based on topotactic solid-state reactions or high-pressure synthesis methods have been reported for several structural frameworks. They have led to the various mixed-oxyanion crystalline phases characterized by different levels of the H -/O 2exchange-ability [6][7][8][9][10][11][12][13][14] . More recently, an alternative approach for the synthesis of oxyhydride-type functional materials was suggested and realized by means of the controllable oxidation of a metal-hydrogen system 15,16 .…”