Critically evaluated ceramic phase diagrams
from 1898 to today


What is included with the ACerS-NIST Phase Equilibria Diagram Database products

  • The largest database of over 33,000 diagrams with critical information and commentaries for inorganic materials comprising ceramic and glass compositions, raw materials, salts and minerals
  • Powerful, user-friendly search interface
  • PDF versions of diagrams and commentary, printable with book-quality resolution
  • Analysis software to directly determine compositions, temperatures and other information from the diagrams without rulers and calculators
  • Available on a USB drive for Windows® computers and as an online subscription, with both single and multiple-user versions

Understanding phase equilibria in ceramic systems is central to the use and development of materials in refractories, glass, and other high-temperature technologies. Phase equilibria diagrams answer questions about processing and use constraints of a ceramic or glass component in high-temperature or high-pressure environments. For an introductory text on the use and interpretation of phase diagrams, please download General Discussions of Phase Diagrams by F.P. Hall, H. Insley, E.M. Levin, H.F. McMurdie and C.R. Robbins.

Call for Contributing Editors

Earn recognition and compensation for providing and evaluating new phase equilibria diagrams.


available material system

The ACerS-NIST PHASE product is the largest collection of data on compositions, phase structure and phase transition temperatures for inorganic materials.  Other phase equilibria collections may have some inorganic compounds, but their focus is on other material types such as metals and alloys, or organic systems.  Gathered from critically-evaluated literature sources going back to 1898, PHASE covers a wide range of compositions, including but not limited to:

  • Oxide systems and mixed systems with oxides for electrodes, catalysts, electroceramics, magneto-resistors, thermistors, capacitors, nuclear fuel/waste, ion conductors and more
  • Chalcogenides such as sulfides and selenides for thermoelectrics, optoelectronics, photovoltaics, etc.
  • Pnictide systems such as nitrides and arsenides for optical materials, sensors, detectors, photovoltaics, etc.
  • Actinide and Rare Earth systems containing U, Th, Pu, Ce, Eu, Gd for nuclear materials research and luminescence, etc.
  • Oxy-cation systems such as molybdates and vanadates
  • Semiconductors – Si, Ge, Sn
  • Group 3 systems – B, Al, Ga, In, Tl
  • Group 4 systems – carbides, silicides for high temperature systems
  • Glass systems – silicates, borosilicates
  • Salts and minerals

Want to see if your system is included in the database? Download the demonstration version and search the cumulative index.

Search Interface
  • Search by elements and components with many boolean operations built in for narrowing or expanding your results. Or view the cumulative index.
  • Not sure of the ideal element combination? Search by application or other text in the commentaries.
  • The preview window gives insight into the format of the phase equilibria diagrams within the PED figure so you can choose the best one for your needs.
  • View the complete Figure (PDF) or view/analyze the diagram using the PED viewer
information formats
  • Each PED Figure consists of the diagrams and commentary for a single chemical system. The commentary lists the information used to generate the diagram(s).  Many Figures also contain comments about applications, new information on the chemical system, etc.  Each Figure is formatted for easy reading and printing in book-quality resolution. Download an example Figure.
  • The PED Diagrams are formatted to be viewed and analyzed in the PED Viewer.  The NEW PED Viewer is a browser-based graphics analysis program that uses the engine from PED Editor, the program developed at NIST by Eric Boesch.  The Viewer allows users to extract temperature and composition information, follow solidus and liquidus lines, view diagrams on both mole and mass bases, and even swap axes to enable viewing according to the needs of the researcher.  Give the Viewer a test drive (go to Phase Demo page).
product Formats

PHASE USB – a physical USB stick containing the database and software. It is loaded onto your local personal computer that runs the Windows® 7 or 10 operating system; no internet required. The PHASE USB product is a one-time purchase that can be used for many years. However, when new diagrams are added, updates to the PHASE USB product carry must be purchased, usually at a significantly discount price depending on which version is being upgraded.

PHASE ONLINE – a cost-effective and convenient subscription web-based service that must be renewed annually. The database is always current for this service.  Not tied to any one workstation, PHASE ONLINE can be accessed from any computer connected to the internet. This is the only format available to MAC and Chomebook users.

PHASE BOOKS – Need to complete your book library or replace a damaged copy? ACerS has a very limited number of the some of the original volumes of phase diagrams used to create Phase Equilibria Diagram products. Click here to see what is currently available.


Single-user versions of both PHASE USB and PHASE ONLINE allow one person at a time to search the database and view the diagrams.

Multi-user PHASE USBs allow loading of the software onto up to 10 PCs

Multi-user PHASE ONLINE subscriptions allow 10 username/password combinations

Library PHASE ONLINE subscriptions allow unlimited simultaneous users via IP Authentication