pair distribution function analysis of nanocrystalline functional materials: the case of TiO-bronze nanocrystals in Li-ion battery electrodes.

Structural modelling of pair distribution function (PDF) data of complex functional materials can be highly challenging. To aid the understanding of complex PDF data, this article demonstrates a toolbox for PDF analysis. The tools include denoising using principal component analysis together with the , and apps available through the online service 'PDF in the cloud' (, https://pdfitc.

Selective Synthesis of Defect-Rich LaMnO by Low-Temperature Anion Cometathesis.

The synthesis of complex oxides at low temperatures brings forward aspects of chemistry not typically considered. This study focuses on perovskite LaMnO, which is of interest for its correlated electronic behavior tied to the oxidation state and thus the spin configuration of manganese. Traditional equilibrium synthesis of these materials typically requires synthesis reaction temperatures in excess of 1000 °C, followed by subsequent annealing steps at lower temperatures and different (O) conditions to manipulate the oxygen content postsynthesis (e.

An Amorphous Phase Precedes Crystallization: Unraveling the Colloidal Synthesis of Zirconium Oxide Nanocrystals.

One can nowadays readily generate monodisperse colloidal nanocrystals, but the underlying mechanism of nucleation and growth is still a matter of intense debate. Here, we combine X-ray pair distribution function (PDF) analysis, small-angle X-ray scattering (SAXS), nuclear magnetic resonance (NMR), and transmission electron microscopy (TEM) to investigate the nucleation and growth of zirconia nanocrystals from zirconium chloride and zirconium isopropoxide at 340 °C, in the presence of surfactant (tri--octylphosphine oxide). Through E1 elimination, precursor conversion leads to the formation of small particles (less than 2 nm in diameter).

Designing Glass and Crystalline Phases of Metal-Bis(acetamide) Networks to Promote High Optical Contrast.

Owing to their high tunability and predictable structures, metal-organic materials offer a powerful platform to study glass formation and crystallization processes and to design glasses with unique properties. Here, we report a novel series of glass-forming metal-ethylenebis(acetamide) networks that undergo reversible glass and crystallization transitions below 200 °C. The glass-transition temperatures, crystallization kinetics, and glass stability of these materials are readily tunable, either by synthetic modification or by liquid-phase blending, to form binary glasses.

Evaluation of the polymorphic forms of ritonavir and lopinavir in raw materials and co-milled systems.

Recently, the U.S. Food and Drug Administration (FDA) approved the first oral antiviral drug to treat mild to moderate cases of coronavirus disease.

Real-space texture and pole-figure analysis using the 3D pair distribution function on a platinum thin film.

An approach is described for studying texture in nanostructured materials. The approach implements the real-space texture pair distribution function (PDF), txPDF, laid out by Gong & Billinge {(2018 ▸). arXiv:1805.

Liquid and Glass Phases of an Alkylguanidinium Sulfonate Hydrogen-Bonded Organic Framework.

Glassy phases of framework materials feature unique and tunable properties that are advantageous for gas separation membranes, solid electrolytes, and phase-change memory applications. Here, we report a new guanidinium organosulfonate hydrogen-bonded organic framework (HOF) that melts and vitrifies below 100 °C. In this low-temperature regime, non-covalent interactions between guest molecules and the porous framework become a dominant contributor to the overall stability of the structure, resulting in guest-dependent melting, glass, and recrystallization transitions.

Superatomic solid solutions.

In atomic solids, substitutional doping of atoms into the lattice of a material to form solid solutions is one of the most powerful approaches to modulating its properties and has led to the discovery of various metal alloys and semiconductors. Herein we have prepared solid solutions in hierarchical solids that are built from atomically precise clusters. Two geometrically similar metal chalcogenide clusters, CoSe(PEt) and CrTe(PEt), were combined as random substitutional mixture, in three different ratios, in a crystal lattice together with fullerenes.

A high throughput optical method for studying compositional effects in electrocatalysts for CO reduction.

In the problem of electrochemical CO reduction, the discovery of earth-abundant, efficient, and selective catalysts is essential to enabling technology that can contribute to a carbon-neutral energy cycle. In this study, we adapt an optical high throughput screening method to study multi-metallic catalysts for CO electroreduction. We demonstrate the utility of the method by constructing catalytic activity maps of different alloyed elements and use X-ray scattering analysis by the atomic pair distribution function (PDF) method to gain insight into the structures of the most active compositions.

Network-Forming Liquids from Metal-Bis(acetamide) Frameworks with Low Melting Temperatures.

Molten phases of metal-organic networks offer exciting opportunities for using coordination chemistry principles to access liquids and glasses with unique and tunable structures and properties. Here, we discuss general thermodynamic strategies to provide an increased enthalpic and entropic driving force for reversible, low-temperature melting transitions in extended coordination solids and illustrate this approach through a systematic study of a series of bis(acetamide)-based networks with record-low melting temperatures. The low melting temperatures of these compounds are the result of weak coordination bonds, conformationally flexible bridging ligands, and weak electrostatic interactions between spatially separated cations and anions, which collectively reduce the enthalpy and increase the entropy of fusion.

Zirconium Phosphate: The Pathway from Turbostratic Disorder to Crystallinity.

We show how the structural order of nanocrystalline zirconium phosphates (ZrP) is tuned by the synthetic methods and conditions through the use of synchrotron X-ray atomic pair distribution function analysis. With different synthetic route and different phosphoric acid concentrations in the synthesis, the product zirconium phosphates vary from turbostratically disordered nanoscale structures to fully ordered ones. We show that a change in the structural order leads to different ion-exchange properties.