On the relationship between structure and dynamics in a supercooled liquid

We present the dynamic propensity distribution as an explicit measure of the degree to which the dynamics in a liquid over the time scale of structural relaxation is determined by the initial configuration. We then examine, for a binary mixture of soft discs in two dimensions, the correlation between the spatial distribution of propensity and that of two localmeasures of configuration structure: the local composition and local free volume. While the small particles dominate the high propensity population,we find no strong correlation between either the local composition or the local free volume and the propensity. It is argued that this is a generic failure of purely local structural measures to capture the inherently non-local character of collective behaviour.Comment: Published, see below or http://www.iop.org/EJ/abstract/0953-8984/17/49/001/ Editing comments have been remove

STRUCTURE OF Er | Y SUPERLATTICES

The magnetic structure of Er | Y superlattices has been determined by neutron diffraction and squid magnetometry on single crystal samples grown on sapphire substrates by molecular-beam-epitaxy techniques. The turn angle in the Er layers is magneto-elastically "clamped", and in fact locks-in to the commensurate state ω = 2π / 7 below about 35 K. For the [Er13 | Y26] superlattice the low temperature state is not 2π / 7 but can be shifted to that value by a magnetic field, since this state has a net moment of 8 µB / 7 atoms along the c-axis