DevanathanStachurski

Devanathan–Stachurski, often referred to as the Devanathan–Stachurski cell or method, is a widely used electrochemical technique for measuring hydrogen diffusion and permeation through metal membranes. It was developed in the early 1960s by Devanathan and Stachurski and has become a standard tool in hydrogen embrittlement research and diffusion studies.

Principle and apparatus: A thin metal foil or film separates two electrolyte compartments. The entry side is subjected to cathodic polarization to generate atomic hydrogen, which dissolves and diffuses through the metal. The exit side is held at a suitable potential to oxidize or recombine the hydrogen, producing a current that is recorded over time. The measured permeation current is proportional to the hydrogen flux through the membrane, allowing the extraction of diffusion-related properties from time-dependent data.

Operation and analysis: Typical electrolytes are acidic aqueous solutions, and measurements can be performed across a range of temperatures. The transient permeation curve provides the time-lag, from which the diffusion coefficient D can be derived, while the steady-state current yields the permeability P and, with solubility data, the solubility S. Temperature dependence can reveal activation energies for diffusion.

Applications and limitations: The method is widely used to characterize hydrogen transport in steels, nickel, palladium, titanium, and other metals, to assess hydrogen embrittlement susceptibility, and to evaluate coatings and surface treatments. Limitations include surface effects, edge leaks, and the need for clean, defect-free membranes; accurate interpretation requires careful control of experimental conditions.

Legacy: The Devanathan–Stachurski cell remains a foundational technique in materials science, frequently cited and adapted for modern diffusion and corrosion studies.