Impurity gel samples in superfluid helium: A new state of soft matter

International Conference and Exhibition on Mesoscopic & Condensed Matter Physics

June 22-24, 2015 Boston, USA

L P Mezhov-Deglin1, V B Efimov2 and V V Nesvizhevsky3

1Institute of Solid State Physics, Russia 2Lancaster University, UK 3Institute Laue-Langevin, France

Posters-Accepted Abstracts: J Material Sci Eng

Abstract :

The report should include results of investigations of the structure and properties of the nanocluster impurity condensates in liquid helium-impurity gels consisted of an impurity nanoclusters (dispersion matter or backbone of the gel) and liquid helium (dispersion medium) filling the pores of the gel sample. One of the results of the SANS studies of the â�?�?deuteriumâ�? ethanol gel sample is shown below. Cold neutron scattering on the C2D5OD gel sample in superfluid He-II (T=1.6 K, curves 1 and 2) and in normal liquid helium (T=4.2 K, curves 3 and 4). It could be estimated that the mean size of the impurity clusters in the sample backbone is d~10-15 nm at liquid helium temperatures. On heating the sample above 5 K in He vapor atmosphere one could observed the decay of the gel resulting in the creation of a fine powder at the bottom of the experimental cell. Judging on the X-ray measurements the structure of the powder particles is amorphous till the liquid nitrogen temperatures and with further heating of the sample one could observe the amorphous-crystalline phase transitions.

Biography :

Email: mezhov@issp.ac.ru