Senior Theses

Publication Date


Document Type

Thesis (Open Access)

Degree Name

Bachelor of Science in Physics



Faculty Advisor(s)

Michael Crosser (Thesis Advisor)
Jennifer Heath & Joelle Murray (Committee Members)

Subject Categories

Condensed Matter Physics | Engineering Physics | Physics | Power and Energy


When electric potentials are applied from an electrolytic fluid to a metal, a double layer capacitor, Cdl, develops at the interface. The layer directly at the interface is called the Stern layer and has a thickness equal to roughly the size of the ions in the fluid. The next layer, the diffuse layer, arises from the gathering of like charges in the Stern layer. This layer is the distance needed for ionic charges to return to equilibrium. This distance, called the Debye length, λ, depends on the square root of the electrolyte concentration. To study the properties of the diffuse layer, we measure C of a cylindrical capacitor using different concentrations of electrolyte solutions in the system we machined. We found that the initial model, which only depended on the Debye length, was not sufficient to predict the capacitance in complex electrolytes where the Stern layer was not nearly symmetric.