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Thermodynamics

Thermodynamics research at NIST helps our industrial and scientific partners develop more efficient and reliable processes by improving our understanding of how the arrangement of matter and energy impact the properties of physical and chemical systems.

Thermodynamic Data Included in Phase-Based Data Repository

MGI diagram

An essential part of the MGI is the development of phase-based data repository. Phase-based data are important for many applications, including the development of CALPHAD-based multicomponent databases. The phase-based data include zero-dimensional, one-dimensional, two-dimensional, and three-dimensional data. Examples of some of the phase-data included are phase transformation temperatures (e.g. melting, solidus, solvus), lattice parameters, thermal expansion, elastic constants, and diffusion coefficients and compositions profiles. These data are reported as functions of composition, temperature and/or pressure.

This repository consists of three data sources:

  • Curated experimental and computational multicomponent alloy data in support of the development Co-based superalloys. Currently the data are focus on diffusion data and transition temperatures. These data are curated using the NIST Materials Data Curation System. This collection is being developed in conjunction with CHiMaD.
  • Thermodynamic Research Center Data provides access to thermophysical property data with a focus on unary, binary, and ternary metal systems through a free online web application and associated API. All data are from original experimental publications and include full provenance and critically evaluated uncertainty.
  • Self diffusion and impurity diffusion coefficient data (experimental and computational) are searchable via the periodic table.

News and Updates

Making the DNA Melt Curve More Accurate

DNA is not only the blueprint of life; it has become the backbone for making tiny structures that can be inserted into the human body to diagnose and treat

A New Way to Measure Nearly Nothing

Many semiconductor fabricators and research labs are under increasing pressure from, of all things, vacuum. These facilities need to remove greater amounts of

Projects and Programs

Vapor Sampling in the Field

We develop and deploy portable vapor sampling instruments to collect detailed chemical information in the field, in sampling situations where the laboratory is

Publications

Tools and Instruments

Piston gauges and pressure transducers

Piston gauges are used to calibrate customer piston gauges and pressure sensing devices. Piston gauges are calibrated via a direct comparison to another piston

Low Pressure Gauges

NIST has developed best-in-the-world primary standard pressure measurement capabilities for pressures spanning the range of 0.01 Pa to 360 kPa through the

Vacuum Gauges

Most calibrations of vacuum gauges are based on a known gas flow rate that is generated by one of two flow meters that operate at constant pressure. The "piston

Leak Artifacts

Leak artifacts are calibrated in the range 1 x 10-6 to 1 x 10-13 mol/s (2 x 10-2 to 2 x 10-9 std. cm3/s at 0 °C). The calibration can be performed directly

Awards

Standard Reference Data

  • REFPROP - NIST Reference Fluid Thermodynamic and Transport Properties Database (REFPROP): Version 9.1
    • New release expected October 2017 - Version 10. Purchase version 10 for $325.00 now! Receive version 9.1 now and version 10 when it is released.

Thermodynamics Research Center

The Thermodynamics Research Center (TRC) performs several functions related to providing state-of-the-art thermodynamic data:

  • Compiles and evaluates experimental data
  • Develops tools and standards for archival and dissemination of thermodynamic data, especially critically evaluated data
  • Develops electronic database products
  • Maintains a web-repository of published data in the THERMOML ARCHIVES, stored in THERMOML  — an XML format developed by TRC for the representation of thermodynamic data