wookiemeister said:
it might be a chemical reaction with the metal
That makes sense, but they’ve already eliminated that hypothesis.
> It was supposed to be a routine experiment …
A ROUTINE experiment measuring the electrical properties of a thin film of laughing gas at 40 Kelvin? I’ve got to get myself assigned to that research organisation.
Full article here
http://pubs.rsc.org/en/content/articlepdf/2014/cp/c4cp03659j
Spontelectrics form a new group of solid state materials
whose salient characteristic is that they exhibit a spontaneous
electric field within the bulk of the solid.
It is evident that the properties of spontelectrics
arise through collective effects resulting in the orientation
of permanent dipole moments of the constituent species.
However it remains unclear whether dipole–dipole interactions
between the active species are an essential ingredient of the
physics which leads to this orientation
1) On forming a film by gas phase deposition under ultrahigh
vacuum (UHV) of a spontelectric material, a polarization
potential, typically of several volts, appears spontaneously on
the surface of the film.
2) This potential, linearly proportional to the thickness of the
film, may be either positive or negative and gives rise to a
corresponding spontelectric field in the film.
3) The spontelectric field depends on both the nature of the
material which is deposited and on the temperature at which
the film is deposited. The field for any substance is in general
less for higher temperatures (save for methyl formate deposited
at Z80 K).
4) At greater than a certain temperature of deposition, no
spontelectric effect can be observed.
5) Warming of a spontelectric film causes at first little change
in the spontaneous potential on the surface of the film, but a
critical temperature is reached at which the spontelectric effect
decays abruptly.
6) The nature of the substrate surface, upon which spontelectric
films are deposited, has essentially no bearing on the
value of the spontelectric field within the film.
Here we address the following questions: (i) how does the
degree of dipole orientation change as the spontelectric species
are removed physically from one another by dilution in a solid
matrix of an inert gas? (ii) Is there some average physical
separation between species at which the spontelectric effect
can no longer be observed?