Temperature-controlled neutron reflectometry sample cell suitable for study of photoactive thin films

Citation

Yager, K.G.; Tanchak, O.M.; Barrett, C.J.; Watson, M.J.; Fritzsche, H. "Temperature-controlled neutron reflectometry sample cell suitable for study of photoactive thin films" Review of Scientific Instruments 2006, 77 045106.
doi: 10.1063/1.2194090

Summary

A new sample cell was designed, built, and validated. It enables neutron reflectometry measurements on photo-active thin films to be performed before, after and during illumination with laser light. This cell is thus useful for studies of photo-resists, photonic crystals, and many others. The cell also enables simultaneous control of ambient atmosphere and sample temperature. Cell validation is performed by irradiating azobenzene thin films.

Abstract

We describe a novel cell design intended for the study of photoactive materials using neutron reflectometry. The cell can maintain sample temperature and control of ambient atmospheric environment. Critically, the cell is built with an optical port, enabling light irradiation or light probing of the sample, simultaneous with neutron reflectivity measurements. The ability to measure neutron reflectivity with simultaneous temperature ramping and/or light illumination presents unique opportunities for measuring photoactive materials. To validate the cell design, we present preliminary results measuring the photoexpansion of thin films of azobenzene polymer.