  Many technologies based on cells containing alkali-metal atomic vapor benefit
from the use of anti-relaxation surface coatings in order to preserve atomic
spin polarization. In particular, paraffin has been used for this purpose for
several decades and has been demonstrated to allow an atom to experience up to
10,000 collisions with the walls of its container without depolarizing, but the
details of its operation remain poorly understood. We apply modern surface and
bulk techniques to the study of paraffin coatings, in order to characterize the
properties that enable the effective preservation of alkali spin polarization.
These methods include Fourier transform infrared spectroscopy, differential
scanning calorimetry, atomic force microscopy, near-edge X-ray absorption fine
structure spectroscopy, and X-ray photoelectron spectroscopy. We also compare
the light-induced atomic desorption yields of several different paraffin
materials. Experimental results include the determination that crystallinity of
the coating material is unnecessary, and the detection of C=C double bonds
present within a particular class of effective paraffin coatings. Further study
should lead to the development of more robust paraffin anti-relaxation
coatings, as well as the design and synthesis of new classes of coating
materials.
