Photo of John W. Cahn

John W. Cahn

  • National Medal of Science
  • Chemistry

For his pioneering work on thermodynamics and kinetics of phase transitions and diffusion, on interfacial phenomena, and for his contributions to the understanding of periodic and quasi-periodic structures.

An alloy is a mixture of metals or a mixture of a metal with another element to improve their properties. The more we rely on technology, the more metal alloys are used in electronics like laptops and smartphones. These everyday items could not have been possible without the influence of materials scientist John W. Cahn and the Cahn-Hillard, and Allen-Cahn equations.

The Cahn-Hillard equation explains why some unalike items, like oil and water, distance themselves from each other instead of combine. This equation has been used to explain other phenomena outside of materials science as well. Astronomers have applied this equation to discover how galaxies form and sociologists have used it to determine why people migrate to more populated areas, rather than areas with lower population density.

Similar to the Cahn-Hillard solution, the Allen-Cahn equation seeks to explain the phenomenon of phase transitions in iron alloys, which is crucial in creating metals that are used in medical devices, military and aerospace fields and construction materials.

By Kristen Brida