Neutron scattering study of nitrogen adsorbed on basal-plane-oriented graphite

NEUTRONS AND 2 D ADSORBED PHASESNEUTRON SCATTERING FROM 36Ar AND 4He FILMS

“…The high temperature phase of the monolayer, when interpreted via this Warren formalism, has a nearestneighbour distance of 4.26 Hi, which matches the commensurate phase. This is similar to what was found for N2 [5], indicating the existence of a registered liquid.…”

“…It is not astonishing that the trial experiment was chosen to be N, adsorbed on grafoil [5], and with this successfully done, a study of the separated isotope 36Ar was initiated. Diffraction profiles from monolayers of 36Ar are shown in figure 1, using neutron energies of 13 meV (i.e., wavelength X = 2.5A).…”

Melting transition of two-dimensional crystals

“…27 It fbllows from the existence of nonregistered monolayer phases on graphite that interatomic forces in the monolayers must play the dominant part in determining the monolayer structure. 7 This implies that the conditions for applying an 1deal monolayer theory are well satisfied.…”

“…We do not have an explanation of the decrease of melting temperature T M with increasing x as exhibited by Fig. 2 7 have observed a denser phase where the melting transition is continuous. Because this structure is not constrained by epitaxy 30°-rotated domains are energetically possible and we propose therefore that the continuous nature of this PT arises from the effect explained in Sec.…”

“…(7) is due to the test source field and the second term results from the stress excerted by the surrounding dipoles. u.u (Ref.…”