Binary phase

Not to be confused with Two-phase (disambiguation).

In materials chemistry, a binary phase or binary compound is a chemical compound containing two different elements. Some binary phase compounds are molecular, e.g. carbon tetrachloride (CCl₄). More typically binary phase refers to extended solids. Famous examples zinc sulfide, which contains zinc and sulfur, and tungsten carbide, which contains tungsten and carbon.^[1]

Sodium chloride is a famous binary phase. It features two elements: Na and Cl.

Phases with higher degrees of complexity feature more elements, e.g. three elements in ternary phases, four elements in quaternary phases.

References

1. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.