"MnAlN" is Really MnN.

We investigate the synthesis of antiperovskite "MnAlN" using the published synthesis procedure, as well as several new reaction pathways. In each case, only a combination of antiperovskite MnN and MnAl or precursors is obtained. The identity of the obtained antiperovskite phase is unambiguously determined to be MnN via synchrotron powder X-ray diffraction (SPXRD), X-ray absorption spectroscopy (XAS), and magnetometry.

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.

Thiocyanate-Stabilized Pseudo-cubic Perovskite CH(NH)PbI from Coincident Columnar Defect Lattices.

α-FAPbI (FA = CH(NH)) with a cubic perovskite structure is promising for photophysical applications. However, α-FAPbI is metastable at room temperature, and it transforms to the δ-phase at a certain period of time at room temperature. Herein, we report a thiocyanate-stabilized pseudo-cubic perovskite FAPbI with ordered columnar defects (α'-phase).

nmfMapping: a cloud-based web application for non-negative matrix factorization of powder diffraction and pair distribution function datasets.

A cloud-hosted web-based software application, nmfMapping, for carrying out a non-negative matrix factorization of a set of powder diffraction or atomic pair distribution function datasets is described. This application allows structure scientists to find trends rapidly in sets of related data such as from in situ and operando diffraction experiments. The application is easy to use and does not require any programming expertise.

Correlating Broadband Photoluminescence with Structural Dynamics in Layered Hybrid Halide Perovskites.

The emission of white light from a single material is atypical and is of interest for solid-state lighting applications. Broadband light emission has been observed in some layered perovskite derivatives, PbBr ( = -NH), and correlates with static structural distortions corresponding to out-of-plane tilting of the lead bromide octahedra. While materials with different organic cations can yield distinct out-of-plane tilts, the underlying origin of the octahedral tilting remains poorly understood.

Two-Step Solid-State Synthesis of Ternary Nitride Materials.

Ternary nitride materials hold promise for many optical, electronic, and refractory applications; yet, their preparation via solid-state synthesis remains challenging. Often, high pressures or reactive gases are used to manipulate the effective chemical potential of nitrogen, yet these strategies require specialized equipment. Here, we report on a simple two-step synthesis using ion-exchange reactions that yield rocksalt-derived MgZrN and MgNbN, as well as layered MgMoN.

Selectivity in Yttrium Manganese Oxide Synthesis via Local Chemical Potentials in Hyperdimensional Phase Space.

In sharp contrast to molecular synthesis, materials synthesis is generally presumed to lack selectivity. The few known methods of designing selectivity in solid-state reactions have limited scope, such as topotactic reactions or strain stabilization. This contribution describes a general approach for searching large chemical spaces to identify selective reactions.

Structure and Optical Properties of Layered Perovskite (MA)PbIBr(SCN) (0 ≤ < 1.6).

The layered perovskite (MA)PbI(SCN) (MA = CHNH) is a member of an emerging series of compounds derived from hybrid organic-inorganic perovskites. Here, we successfully synthesized (MA)PbIBr(SCN) (0 ≤ < 1.6) by using a solid-state reaction.

Ferroelastic Phase Transition in Formamidinium Tin(IV) Iodide Driven by Organic-Inorganic Coupling.

Hybrid perovskites are a technologically relevant family of materials, with potential applications in photovoltaics, solid-state lighting, and radiation detection. Interactions between the inorganic octahedral framework and the organic sublattice have been implicated in the structure and optoelectronic properties, but characterization of these interactions has been challenging, because of competition between organic-inorganic coupling and intraoctahedral interactions. Owing to their decreased octahedral connectivity, vacancy-ordered double perovskites present an ideal case study to examine organic-inorganic coupling in hybrid perovskites and their derivatives.

Defect-Accommodating Intermediates Yield Selective Low-Temperature Synthesis of YMnO Polymorphs.

In the synthesis of complex oxides, solid-state metathesis provides low-temperature reactions where product selectivity can be achieved through simple changes in precursor composition. The influence of precursor structure, however, is less understood in solid-state synthesis. Here we present the ternary metathesis reaction (LiMnO + YOCl → YMnO + LiCl) to target two yttrium manganese oxide products, hexagonal and orthorhombic YMnO, when starting from three different LiMnO precursors.

A thermal-gradient approach to variable-temperature measurements resolved in space.

Temperature is a ubiquitous environmental variable used to explore materials structure, properties and reactivity. This article reports a new paradigm for variable-temperature measurements that varies the temperature continuously across a sample such that temperature is measured as a function of sample position and not time. The gradient approach offers advantages over conventional variable-temperature studies, in which temperature is scanned during a series measurement, in that it improves the efficiency with which a series of temperatures can be probed and it allows the sample evolution at multiple temperatures to be measured in parallel to resolve kinetic and thermodynamic effects.

Catalytic behavior of hexaphenyldisiloxane in the synthesis of pyrite FeS.

Functional small molecules afford opportunities to direct solid-state inorganic reactions at low temperatures. Here, we use catalytic amounts of organosilicon molecules to influence the metathesis reaction: FeCl2 + Na2S2 → 2NaCl + FeS2. Specifically, hexaphenyldisiloxane ((C6H5)6Si2O) is shown to increase pyrite yields in metathesis reactions performed at 150 °C.

Amide-Assisted Synthesis of Iron Germanium Sulfide (FeGeS) Nanostars: The Effect of LiN(SiMe) on Precursor Reactivity for Favoring Nanoparticle Nucleation or Growth.

Olivine FeGeS has been identified as a promising photovoltaic absorber material introduced as an alternate candidate to iron pyrite, FeS. The compounds share similar benefits in terms of elemental abundance and relative nontoxicity, but FeGeS was predicted to have higher stability with respect to decomposition to alternate phases and, therefore, more optimal device performance. Our initial report of the nanoparticle (NP) synthesis for FeGeS was not well understood and required an inefficient 24 h growth to dissolve an iron sulfide impurity.

Yttrium Manganese Oxide Phase Stability and Selectivity Using Lithium Carbonate Assisted Metathesis Reactions.

In solid-state chemistry, stable phases are often missed if their synthesis is impractical, such as when decomposition or a polymorphic transition occurs at relatively low temperature. In the preparation of complex oxides, reaction temperatures commonly exceed 1000 °C with little to no control of the reaction pathway. Thus, a prerequisite for exploring the synthesis of complex oxides is to identify reactions with intermediates that are kinetically competent at low temperatures, as provided by assisted metathesis reactions.

Low-temperature synthesis of superconducting iron selenide using a triphenylphosphine flux.

Many functional materials have relatively low decomposition temperatures (T≤ 400 °C), which makes their synthesis challenging using conventional high-temperature solid-state chemistry. Therefore, non-conventional techniques such as metathesis, hydrothermal, and solution chemistry are often employed to access low-temperature phases; the discovery of new chemistries is needed to expand access to these phases. This contribution discusses the use of triphenylphosphine (PPh) as a molten flux to synthesize superconducting iron selenide (FeSe) at low temperature (T = 325 °C).

Influence of organic cation planarity on structural templating in hybrid metal-halides.

Controlling the connectivity and topology of solids is a versatile way to target desired physical properties. This is especially relevant in the realm of hybrid halide semiconductors, where the long-range connectivity of the inorganic substructural unit can lead to significant changes in optoelectronic properties such as photoluminescence, charge transport, and absorption. We present a new series of hybrid metal-halide semiconductors, (phenH)BiI·HO, (2,2-bpyH)BiI, (BrbpyH)BiI·HO, (phenH)PbI·2HO, and (2,2-bpyH)PbI where (phenH) = 1,10-phenanthroline-1,10-diium, (2,2-bpyH) = 2,2'-bipyridine-1,1'-diium and (BrbpyH) = 6,6'-dibromo-2,2'-bipyridium.

Hybrid Charge-Transfer Semiconductors: (CH)SbI, (CH)BiI, and Their Halide Congeners.

Hybrid metal halides yield highly desirable optoelectronic properties and offer significant opportunity due to their solution processability. This contribution reports a new series of hybrid semiconductors, (CH)MX (M = Bi, Sb; X = Cl, Br, I), that are composed of edge-sharing MX chains separated in space by π-stacked tropylium (CH) cations; the inorganic chains resemble the connectivity of BiI. The Bi compounds have blue-shifted optical absorptions relative to the Sb compounds that span the visible and near-IR region.

Synthetic control over orientational degeneracy of spacer cations enhances solar cell efficiency in two-dimensional perovskites.

Two-dimensional perovskites have emerged as more intrinsically stable materials for solar cells. Chemical tuning of spacer organic cations has attracted great interest due to their additional functionalities. However, how the chemical nature of the organic cations affects the properties of two-dimensional perovskites and devices is rarely reported.

Selective Formation of Yttrium Manganese Oxides through Kinetically Competent Assisted Metathesis Reactions.

The synthesis of complex oxides requires high temperatures to overcome barriers imparted by solid-state diffusion; as such, reactions typically yield the most stable polymorph for a given composition. To synthesize new or metastable complex oxides, kinetically competent reactions with lower initial energy barriers must be devised to control the reaction pathway and resulting products. This contribution details the selective synthesis of different yttrium manganese oxides through assisted metathesis reactions between MnO, YCl, and ACO under flowing oxygen; where A = Li, Na, K.

Slow magnetic relaxation in octahedral low-spin Ni(iii) complexes.

Herein we report the first examples of single-molecule magnet (SMM) behaviour in = 1/2 Ni(iii) complexes. We find that low-spin 3d -[Ni(cyclam)(X)]Y complexes (cyclam = 1,4,8,11-tetraazacyclotetradecane; X and Y are singly charged anions) exhibit field-induced slow relaxation of magnetization for O-donor axial ligands (nitrate) but not for N-donor variants (isothiocyanate). Experimental and electronic structure computational investigations indicate that intrinsic spin polarisation of low-spin Ni(iii) is modulated significantly by local coordination geometry and supramolecular interactions.

A high precision gas flow cell for performing in situ neutron studies of local atomic structure in catalytic materials.

Gas-solid interfaces enable a multitude of industrial processes, including heterogeneous catalysis; however, there are few methods available for studying the structure of this interface under operating conditions. Here, we present a new sample environment for interrogating materials under gas-flow conditions using time-of-flight neutron scattering under both constant and pulse probe gas flow. Outlined are descriptions of the gas flow cell and a commissioning example using the adsorption of N by Ca-exchanged zeolite-X (NaCaAlSiO,x ≈ 38).