Objectives:
-To enable rapid materials development for advanced manufacturing applications by using semantic theory and design as a basis for database interoperability to provide access to data describing the structure, stability, and properties of inorganic materials.

-To provide a unified crystal-structure database containing both metallic and non-metallic inorganic materials by evaluating and transforming a subset of the crystal structure data within the NIST Metals Structural Database for inclusion into the FIZ/NIST Inorganic Crystal Structure Database.

-To enable database interoperability by designing and relating representations and conventions for crystallographic space groups for a subset of space groups and entries from the Metals database.

-To enable integration of crystal-structure databases into diffraction measurement instrumentation by direct interactions with the user community and instrument and software vendors in order to effect a large and positive economic impact.
 

Background:
Components and devices used in a broad spectrum of technology sectors, e.g., healthcare, communications, energy, and electronics, are manufactured from crystalline inorganic materials. To meet the demands for increased device functionality and decreased manufacturing costs, advanced materials with new or improved properties and optimized processing schemes are continually being developed. Examples of multi-million dollar industries driven by materials advances are microelectronics (Si-based devices), automotive (Pt-alloy catalytic converters), aerospace (ultra-light alloys and composites), solid state lighting (GaN-based devices), and prosthetic devices (ceramic dental crowns).

Development of advanced inorganic materials necessarily begins with the preparation and identification of the constituent chemical and crystallographic phases. An estimated 20,000 X-ray diffractometers and a comparable number of electron microscopes are used daily in materials research and development laboratories for this purpose. Crystalline phases can be identified by their characteristic X-ray, neutron, and electron diffraction patterns by pattern-matching against crystal structure data already determined for phases known to form in a chemical system. Modern, automated diffraction instruments generate large amounts of experimental diffraction data that are compared against information contained in or calculated from crystal structure databases to make phase identifications.

Rapid, unambiguous identification of crystalline phases by diffraction requires comprehensive, accurate, and reliable crystal structure databases that can be quickly and easily searched. As different diffraction techniques and instruments generate data with different content the databases need to be integrated easily into a wide variety of instrument platforms. In addition, crystal structure databases obtained from different sources, or that contain different information relevant to particular materials classes, or that use different representations of information for historical or materials class-specific reasons, need to interoperate. Such interoperability is also essential if the databases are to be easily extensible in terms of new phases or new information fields. Finally, the form of crystal structure databases needs to be such that they can interoperate easily with other materials information databases, for example those containing thermodynamic stability data or materials property data.

Hence, crystal structure databases are central to the core materials science and engineering linkages of processing-structure-properties. Establishing these linkages via crystal structure databases that can be integrated easily into a wide range of measurement platforms and that can interoperate with other structural and non-structural materials databases is critical to manufacturing of advanced components and devices.

Although many materials databases have been built—the internet and personal computers (PCs) provide facile and robust delivery and search mechanisms—information in diverse databases is not uniform or readily combined due to the historical evolution and variable adoption of crystallographic conventions and standards. The variety of scientific and physical representations used in different crystal structure databases poses significant barriers to access by non-experts and to realization of the full benefits of communications and computing power. This circumstance persists in spite of numerous standards activities and acknowledgement of the benefits of interoperability.
 

Page created January 2008

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