Growing length scales in a supercooled liquid close to an interface

@article{kob02b, abstract = {We present the results of molecular dynamics computer simulations of a simple glass former close to an interface between the liquid and the frozen amorphous phase of the same material. By investigating Fs(q, z, t), the incoherent intermediate scattering function for particles that have a distance z from the wall, we show that the relaxation dynamics of the particles close to the wall are much slower than those for particles far away from the wall. For small z the typical relaxation time for Fs(q, z, t) increases as exp[(z-zp)], where and zp are constants. We use the location of the crossover from this law to the bulk behaviour to define a first length scale z. A different length scale is defined by considering the Ansatz Fs(q, z, t) = Fs\bulk(q, t) + a(t) exp-[z/(t)](t), where a(t), (t) and (t) are fit parameters. We show that this Ansatz gives a very good description of the data for all times and all values of z. The length (t) increases for short and intermediate times and decreases again on the time scale of the relaxation of the system. The maximum value of (t) can thus be defined as a new length scale max. We find that z as well as max increase with decreasing temperature. The temperature dependence of this increase is compatible with a divergence of the length scale at the Kauzmann temperature of the bulk system.}, author = {Scheidler, Peter and Kob, Walter and Binder, Kurt and Parisi, Giorgio }, citeulike-article-id = {1821578}, journal = {Philosophical Magazine B}, keywords = {confinement, length-scale, lennard-jones}, month = {February}, number = {3}, pages = {283--290}, posted-at = {2007-10-25 17:55:50}, priority = {0}, title = {Growing length scales in a supercooled liquid close to an interface}, url = {http://www.ingentaconnect.com/content/tandf/tphb/2002/00000082/00000003/art00004}, volume = {82}, year = {2002} }

TY - JOUR ID - kob02b L3 - citeulike-article-id:1821578 N2 - We present the results of molecular dynamics computer simulations of a simple glass former close to an interface between the liquid and the frozen amorphous phase of the same material. By investigating Fs(q, z, t), the incoherent intermediate scattering function for particles that have a distance z from the wall, we show that the relaxation dynamics of the particles close to the wall are much slower than those for particles far away from the wall. For small z the typical relaxation time for Fs(q, z, t) increases as exp[(z-zp)], where and zp are constants. We use the location of the crossover from this law to the bulk behaviour to define a first length scale z. A different length scale is defined by considering the Ansatz Fs(q, z, t) = Fs\bulk(q, t) + a(t) exp-[z/(t)](t), where a(t), (t) and (t) are fit parameters. We show that this Ansatz gives a very good description of the data for all times and all values of z. The length (t) increases for short and intermediate times and decreases again on the time scale of the relaxation of the system. The maximum value of (t) can thus be defined as a new length scale max. We find that z as well as max increase with decreasing temperature. The temperature dependence of this increase is compatible with a divergence of the length scale at the Kauzmann temperature of the bulk system. IS - 3 JF - Philosophical Magazine B EP - 290 TI - Growing length scales in a supercooled liquid close to an interface VL - 82 SP - 283 KW - confinement KW - length-scale KW - lennard-jones AU - Scheidler, Peter AU - Kob, Walter AU - Binder, Kurt AU - Parisi, Giorgio PY - 2002/02// UR - http://www.ingentaconnect.com/content/tandf/tphb/2002/00000082/00000003/art00004 ER -