title: Experimental evidence for fast heterogeneous collective structural relaxation in a supercooled liquid near the glass transition
abstract: We have extended the exploration of microscopic dynamics of supercooled liquids to small wave numbers Q corresponding to the scale of intermediate range order, by developing a new experimental approach for precise data correction for multiple scattering noise in inelastic coherent neutron scattering. Our results in supercooled Ca0.4K0.6(NO3)(1.4) reveal the first direct experimental evidence, after a decade of controversy, that the so-called picosecond process around the glass transition corresponds to a predicted first, faster stage of the structural relaxation. In addition, they show that this process takes the spatial form of fast heterogeneous collective flow of correlated groups of atoms.
authors.affiliation: Los Alamos National Laboratory, MS H805, Los Alamos, New Mexico 87545 and and Hahn-Meitner-Institute, Glienicker Strasse 100, 14109 Berlin, Germany.
authors.initials: M
authors.lastname: Russina
authors.initials: F
authors.lastname: Mezei
authors.initials: R
authors.lastname: Lechner
authors.initials: S
authors.lastname: Longeville
authors.initials: B
authors.lastname: Urban