Oxyhydrides, in which oxide and hydride anions share the same anionic lattice, are relatively rare compounds. LaLiHO belongs to this family. We report the synthesis of LaLiHO by means of an alkali halide flux method, which allows the production of larger quantities of material relative to the usually adopted synthesis routes. Powder X-ray and neutron diffraction studies show that LaLiHO adopts an n = 1 Ruddlesden-Popper (RP)-type structure with an orthorhombic distortion (Immm) due to hydride and oxide anion ordering. No sign of polymorphism is observed. LaLiHO is seen to decompose in an oxygen atmosphere at ∼450 °C into LaLiO. We show that the high mobility of hydride anions close to the decomposition temperature is likely the main factor in inducing the oxidation. The crystal structure of LaLiO is also determined and takes an n = 1 RP-type structure with an orthorhombic distortion (Fmmm). This newly reported large-scale synthesis approach, combined with the proven high thermal stability, is a key factor for potential practical applications of this oxyhydride in real devices.

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As traditional silicon technology is moving fast towards its fundamental limits, all-oxide electronics is emerging as a challenger offering principally different electronic behavior and switching mechanisms. This technology can be utilized to fabricate devices with enhanced and exotic functionality. One of the challenges for integration of complex oxides in electronics is the availability of appreciable low-temperature synthesis routes. Herein we provide a fundamental extension of the materials toolbox for oxide electronics by reporting a facile route for deposition of highly electrically conductive thin films of LaNiO 3 by atomic layer deposition at low temperatures. The films grow epitaxial on SrTiO 3 and LaAlO 3 as deposited at 225°C, with no annealing required to obtain the attractive electronic properties. The films exhibit resistivity below 100 µΩ cm with carrier densities as high as 3.6 • 10 22 cm −3. This marks an important step in the realization of all-oxide electronics for emerging technological devices.

Hydride anion-conducting oxyhydrides have recently emerged as a brand new class of ionic conductors. Here we shed a first light onto their local vibrations, bonding mechanisms, and anion migration properties using the powerful combination of high-resolution inelastic neutron scattering and a set of rigorously experimentally validated density functional theory calculations. By means of charge-density analysis we establish the bonding to be strongly anisotropic; ionic in the perovskite layer and covalent in the rock salt layer. Climbing nudged elastic band calculations allow us to predict the hydride migration paths, which crucially we are able to link to the observed exotic ionic-covalent hybrid bonding nature. In particular, hydride migration in the rock salt layer is seen to be greatly hindered by the presence of covalent bonding, forcing in-plane hydride migration in the perovskite layer to be the dominant transport mechanism. On the basis of this microscopic insight into the transport and bonding, we are able to propose future candidates for materials that are likely to show enhanced hydride conductivity.