Simulated NMR Line Shapes for Random Ordering in Solid Hydrogen Films

Abstract

Random disorder was seen for ortho‐H2 concentrations 0.48 < x[o‐H2]<0.69 at temperatures [∼200 mK ⩽ T ⩽ ∼600 mK] in submonolayer H2 films adsorbed on hexagonal boron nitride. The NMR line shapes for the adsorbed H2 samples were distinct from those of bulk samples because a crystal field is introduced by the substrate in addition to the electrostatic quadrupole‐quadrupole interactions between two adjacent H2 molecules. Computer simulations have been carried out to determine the NMR line shapes of solid H2 films for different local order parameters and Guassian broadening functions. The simulated NMR line shapes are presented and discussed.