Perspective: Toward “synthesis by design”: Exploring atomic correlations during inorganic materials synthesis

Abstract

Synthesis of inorganic extended solids is a critical starting point from which realworld functional materials and their consequent technologies originate. However, unlike the rich mechanistic foundation of organic synthesis, with its underlying rules of assembly (e.g., functional groups and their reactivities), the synthesis of inorganic materials lacks an underpinning of such robust organizing principles. In the latter case, any such rules must account for the diversity of chemical species and bonding motifs inherent to inorganic materials and the potential impact of mass transport on kinetics, among other considerations. Without such assembly rules, there is less understanding, less predictive power, and ultimately less control of properties. Despite such hurdles, developing a mechanistic understanding for synthesis of inorganic extended solids would dramatically impact the range of new material discoveries and resulting new functionalities, warranting a broad call to explore what is possible. Here we discuss our recent approaches toward a mechanistic framework for the synthesis of bulk inorganic extended solids, in which either embryonic atomic correlations or fully developed phases in solutions or melts can be identified and tracked during product selection and crystallization. The approach hinges on the application of high-energy x-rays, with their penetrating power and large Q-range, to explore reaction pathways in situ. We illustrate this process using two examples: directed assembly of Zr clusters in aqueous solution and total phase awareness during crystallization from K-Cu-S melts. These examples provide a glimpse of what we see as a larger vision, in which large scale simulations, data-driven science, and in situ studies of atomic correlations combine to accelerate materials discovery and synthesis, based on the assembly of well-defined, prenucleated atomic correlations. C 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license

A Hydride Route to Ternary Alkali Metal Borides: A Case Study of Lithium Nickel Borides

“…This computational success should be complemented by the targeted synthesis of compounds with desired functionality and by the development of rapid synthetic methods allowing for the vast compositional screening of phase space . However, the synthesis‐by‐design of energy‐relevant inorganic materials is often hampered by slow diffusion rates, necessitating high temperature regimes, in which only thermodynamically stable products can be obtained . The synthesis of compounds using precursors with drastically different reactivities brings the synthetic challenge to the next level of complexity.…”

“…[1][2][3] However,t he synthesis-by-design of energy-relevant inorganic materials is often hampered by slow diffusion rates, necessitating high temperature regimes, in which only thermodynamically stable products can be obtained. [2][3][4][5][6] The synthesis of compounds using precursors with drastically different reactivities brings the synthetic challenge to the next level of complexity.F or example, boridesa re challenging synthetic targets. Boride synthesis is hampered by the inertness and high meltingp oint of elemental boron (2349 K).…”

A multi-purpose reaction cell for the investigation of reactions under solvothermal conditions

“…Such radiation is only available at a few facilities and allows penetration of reaction chambers and solvent volumes as well as fast measurements to follow reactions. These methods involve X-ray diffraction (XRD), [9][10][11][12][13] X-ray absorption spectroscopy (XAS), 14,15 small-angle X-ray scattering (SAXS), and total scattering and pair distribution analysis (PDF) [15][16][17] that are universally applicable and allow analysis of a diverse spectrum of chemical compounds and materials. With the development of 3rd generation synchrotron sources and better detectors, the prospects of in situ analyses have dramatically increased, yielding a far better time resolution and signal quality.…”

“…As each analysis technique only provides a part of the information required to entirely understand the mechanism of a chemical reaction, it is often necessary to combine several characterization techniques. 1,5,6,14,15,17 In consideration of this, it is ideal to use a reaction cell that can be utilized for different analysis techniques to avoid introducing any new parameters like changes in volume, shape of cell, and stirring efficiency that might change when shifting to a different experimental setup. Additionally the reaction cell should be easy to operate while working as close as possible to laboratory conditions to ensure that the results from previous ex situ investigations can be reproduced well.…”

Preface: Special Topic on Materials Genome

“…As Pfeif and Kroenlein 9 point out, however, high-throughput tools do not yet exist for many material properties such as melting temperature and yield. Soderholm and Mitchell 13 propose combining large-scale simulations, data-driven science, and in situ studies of atomic correlations in order to learn how to design and control the synthesis of inorganic material. And Hattrick-Simpers et al 15 review the field of automated phase diagram generation via high-throughput experimentation and consider how emerging computational approaches will accelerate these methods.…”