I. V. Kalinin, E. I. Kats, M. Koza, V. V. Lauter, H. Lauter, A. V. Puchkov, “Neutron diffraction study of polycrystalline <nobr>$^4\mathrm{He}$</nobr> in a porous medium”, Pis'ma v Zh. Èksper. Teoret. Fiz., 2013, Volume 98, Issue 4,Pages <nobr>261

CONDENSED MATTER

Neutron diffraction study of polycrystalline $^4\mathrm{He}$ in a porous medium

I. V. Kalinin^a, E. I. Kats^b, M. Koza^c, V. V. Lauter^d, H. Lauter^d, A. V. Puchkov^a

^a Institute for physics and power engineering named after A. I. Leypunsky, Obninsk, Kaluga region
^b L. D. Landau Institute for Theoretical Physics, Russian Academy of Sciences
^c Institut Laue-Langevin, Grenoble
^d Oak Ridge National Laboratory

Abstract: The elastic (diffraction) component of the neutron scattering cross section, which carries information on the atomic structure of solid helium confined in silica aerogel, has been studied. Analysis of the crystalline structure of solid helium in a porous medium, which is determined from the existing neutron diffraction data, indicates that the superfluid phase is localized inside a hexagonal close-packed phase and is not present in a body-centered cubic crystal. It has also been revealed that the addition of the $^3\mathrm{He}$ isotope changes the structure of solid helium and hardly affects the formation of a superfluid phase.

Received: 05.07.2013
Revised: 19.07.2013

DOI: 10.7868/S0370274X13160108