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In the pursuit of urgently needed, energy dense solid-state batteries for electric vehicle and portable electronics applications, halide solid electrolytes offer a promising path forward with exceptional compatibility against high-voltage oxide electrodes, tunable ionic conductivities, and facile processing. For this family of compounds, synthesis protocols strongly affect cation site disorder and modulate Li+ mobility. In this work, we reveal the presence of a high concentration of stacking faults in the superionic conductor Li3YCl6 and demonstrate a method of controlling its Li+ conductivity by tuning the defect concentration with synthesis and heat treatments at select temperatures. Leveraging complementary insights from variable temperature synchrotron X-ray diffraction, neutron diffraction, cryogenic transmission electron microscopy, solid-state nuclear magnetic resonance, density functional theory, and electrochemical impedance spectroscopy, we identify the nature of planar defects and the role of nonstoichiometry in lowering Li+ migration barriers and increasing Li site connectivity in mechanochemically synthesized Li3YCl6. We harness paramagnetic relaxation enhancement to enable 89Y solid-state NMR and directly contrast the Y cation site disorder resulting from different preparation methods, demonstrating a potent tool for other researchers studying Y-containing compositions. With heat treatments at temperatures as low as 333 K (60 °C), we decrease the concentration of planar defects, demonstrating a simple method for tuning the Li+ conductivity. Findings from this work are expected to be generalizable to other halide solid electrolyte candidates and provide an improved understanding of defect-enabled Li+ conduction in this class of Li-ion conductors.

Three-dimensional carbon-based structures have proven useful for tailoring material properties in structural mechanical and energy storage applications. One approach to obtain them has been by carbonization of selected metal-organic frameworks (MOFs) with catalytic metals, but this is not applicable to most common MOF structures. Here, we present a strategy to transform common MOFs, by guest inclusions and high-temperature MOF-guest interactions, into complex carbon-based, diatom-like, hierarchical structures (named for the morphological similarities with the naturally existing diatomaceous species). As an example, we introduce metal salt guests into HKUST-1-type MOFs to generate a family of carbon-based nano-diatoms with two to four levels of structural hierarchy. We report control of the morphology by simple changes in the chemistry of the MOF and guest, with implications for the formation mechanisms. We demonstrate that one of these structures has unique advantages as a fast-charging lithium-ion battery anode. The tunability of composition should enable further studies of reaction mechanisms and result in the growth of a myriad of unprecedented carbon-based structures from the enormous variety of currently available MOF-guest candidates.

High-pressure synchroton X-ray powder diffraction measurements of a sample of purely siliceous zeolite Y were carried out. Rietveld refinement analysis of the powder patterns provides a detailed description of the underlying chemistry and framework distortions at higher pressures.

Sorption, neutron scattering, and temperature desorption experiments points toward the existence of unsaturated Ni(super 2+) sites in VSB-5 that strongly interact with H2. The discovery of unique interactions with molecular hydrogen in these materials should motivate a search for new compounds in this family tailored for H2 uptake.

An alternative route to molybdenum disulfide nanotubes is proposed.

A new study investigates the characterization of the local cation environment and possible site preferences in mixed lithium-sodium chabazites, using solid-state NMR and neutron diffraction.

A study was conducted comparing Monte Carlo simulations and results of calorimetric measurements on the adsorption of chlorocarbons, chloroform and three faujasite type zeolites of trichloroethylene and siliceous faujasite. Quantitative agreement was found between the calculated and observed heats as a function of sorbate loading for all six systems. Decomposition of calculated heats showed that sorbate-sorbate interactions were important to the three zeolite hosts and led to an increase in the adsorption heat.

The structure of the silicate species was determined utilizing the Hartree-Fock technique and the 29Si NMR magnetic shielding constants were subsequently computed using the coupled perturbed Hartree-Fock technique with gauge including atomic orbitals. The silicate monomer was modeled as a neutral fully protonated species, H4SiO4 and as a monoanion-potassium cation pair, H(sub 3)SiO(sub 4)(super -)K(super +). Hydration by up to four and two water molecules, respectively, was also considered.

The role of structure-directing agents during the crystallization stage in the synthesis of two zeolites, siliceous ferrierite and dodecasil-3C, were investigated using x-ray spectroscopic methods. The two zeolites, which contain five-ring building blocks, may be prepared using hexagonal faujasite and pyridine as solvents. According to x-ray measurements, the first contains propylamine while the latter contains both propylamine and pyridine.

Synchrotron x-ray and neutron powder diffraction studies of the crystal structures of siliceous zeolite ferrierite reveal the presence of a Si-O-Si unit with a bond angle of 170 degrees. Crystal structures predicted by lattice energy minimization method agree with the experimental observations. A bond angle correlation helps assign the well-resolved 29Si magic angle spinning NMR spectrum. This assignment helps determine Si/Al ratios in the multiple T-site system and analyze the complex spectra of various aluminosilicate ferrierite samples.

The valence distribution of Fe2+ and Fe3+ in alpha-Fe2PO5 was investigated by the resonant X-ray and neutron powder diffraction using a Rietveld profile refinement program. The direct cation-cation interactions and cation-anion- cation interactions were studied based on the proposition that the two cations belong to two distinct crystallographic sites. The results were then compared with bond valence calculations.

The synthesis of new phases and crystal structures of 11 alkaline earth tartrates, including an unusual [I.sup.3][O.sup.0] framework [Ba(D,L-Tar)] (Tar = [C.sub.4][H.sub.4][O.sub.6.sup.2-]), with 3-D inorganic connectivity is described. The results have shown that the calcium and strontium meso phases are the most thermodynamically stable phases in their systems over a wide temperature range.

The application of nanoindentation and atomic force microscopy to establish the fundamental relationships between mechanical properties and chemical bonding in a dense inorganic-organic framework material, Ce([C.sub.2][O.sub.4])(HC[O.sub.2]) is reported. The study provides insight into vast opportunity to design the mechanical properties of dense hybrid framework materials through the incorporation of organic multifunctional ligands of varying rigidity.

Multiferroic behavior in perovskite-related metal-organic frameworks of general formula [[(C[H.sub.3]).sub.2]N[H.sub.2]M[(HCOO).sub.3], where M = Mn, Fe, Co, and Ni, is described. These compounds have displayed paraelectric-antiferroelectric phase transition behavior in the temperature range 160-185 K, which is associated with an order-disorder transition involving the hydrogen bonded dimethylammonium cations.

Tc[Br.sub.3] and Tc[Br.sub.4] are prepared by reaction between Tc metal and elemental bromine and characterized by using single crystal XRD. The Tc[Br.sub.3] has displayed the Ti[I.sub.3] structure type, the Tc[Br.sub.4] is isomorphous with Tc[Cl.sub.4] and the bromides of technetium are unique and do not match the behavior of Re.

An order-disorder type electrical ordering is described at 156 K in [[(C[H.sub.3]).sub.2]N[H.sub.2]]Zn[(HCOO).sub.3]. A hybrid system with the perovskite architecture is described that has displayed a ferroic transition between paraelectric and antiferroelectric states.

The complete structure of Tc[O.sub.2] obtained from Rietveld refinement with neutron powder diffraction data is presented.

Study is conducted to show that a porous hybrid inorganic/organic material, Na[Ni.sub.3](OH)[(SIP).sub.2] [SIP=5-sulfoisophthalate] (1) strongly binds molecular hydrogen at coordinatively unsaturated metal sites. A combination of [H.sub.2] sorption isotherms, temperature programmed desorption, and inelastic neutron scattering spectroscopy show the existence of a significant number of such strong binding sites in (1) along with other sites where hydrogen is more weakly physisorbed.

Atomic force microscopy (AFM) has been used to study crystal growth in zeolite A. The study demonstrates the power of AFM in imaging crystal growth mechanism in miccrocrystalline materials. The origin and correction of image distortion is described and a general method that is easily adpatable to any microcrystalline powder is presented.

The host-guest hydrogen bonding interactions in case of chloroform in zeolite NaY by neutron scattering is observed. The guest-host interatomic distances shows a significant peak consisting of a doublet at 2.25 and 2.4 Angstrom units and the shoulder at 2.25 Angstrom unit can be ascribed to CH...O guest-host H-bond distance.