Figure 6.

Map of the local Debye-Waller factor <u²> for a range of T showing the heterogeneity of the mobility as T is varied. Particles of high mobility string-like motion are concentrated in filamentary grain boundary like domains that separate regions having relatively strong short range order. The interfacial ordering also bears some similarity to the two-dimensional ordering of a hexatic fluid ¹⁰⁷, as suggested before for the surfaces of metal nanoparticles¹⁰⁸ and for fluids confined to nanopores.¹⁰⁹