Research Interests:

Prof. Hess´s primary research interest is the experimental study of the properties of layers of simple molecules adsorbed on a uniform surface at low temperatures. The substrate is usually graphite, on which it is easy to prepare an atomically clean surface. Phenomena of interest include wetting (that is, growth of a uniform film to macroscopic thickness) or non-wetting by liquid and solid adsorbates; layer-bylayer versus continuous growth, which is related to roughening of the adsorbate free surface; preroughening, which is associated with disordering of the outermost layer; and melting or other phase transitions within individual layers. The amount of adsorbate on the surface is monitored by ellipsometry, an optical technique with a sensitivity of 0.1 to 0.01 molecular layers. Infrared absorption spectroscopy provides more detailed information on the molecules in the film, their concentration, orientation, and interactions.

A current interest is binary mixture films. There are questions relating to such phenomena as the extent of 2-D solubility or segregation of components between layers, and displacement of a preadsorbed monolayer of one component by one or more layers of the other component. The infrared technique is particularly valuable for mixtures, provided suitable molecules are chosen.

Other interests include superfluid properties of liquid helium.

Selected Publications:

Current and Recent Courses:

PHYS 3110: Widely Applied Physics I (Lecturer) Fall

PHYS 3120: Widely Applied Physics (Lecturer) Spring

PHYS 3170: Intermediate Laboratory I (Supervisor) Fall

PHYS 3180: Intermediate Laboratory I (Supervisor) Spring

PHYS 3190: Advanced Laboratory (Supervisor) Both

PHYS 9010: General Physics Research Seminar (Coordinator) Fall

PHYS 9020: Research Talks (Lecturer) Spring

George Hess’s Personal Home Page.