arXiv subjects

A. N. Yudin

Publications and source records attributed to A. N. Yudin.

21 records · Page 2Linked to original sources

arXiv2010

3He NMR in porous media: Inverse Laplace transformation

For the first time the inverse Laplace transform was applied for analysis of 3He relaxation in porous media. It was shown that inverse Laplace transform gives new information about these systems. The uniform-penalty algorithm has been performed to obtain the 3He relaxation times distribution in pores of clay sample. It is possible to obtain pores' sizes distribution by using applicable model. Keywords: inverse Laplace transform, uniform-penalty algorithm, liquid 3He, 3He, He3, He-3, helium-3, pulse nuclear magnetic resonance, clay, porous media.

cond-mat.mtrl-sci↗

arXiv2010

NMR of liquid 3He in clay pores at 1.5 K

In the present work a new method for studying porous media by nuclear magnetic resonance of liquid 3He has been proposed. This method has been demonstrated in an example of a clay mineral sample. For the first time the integral porosity of clay sample has been measured. For investigated samples the value of integral porosity is in the range of 10-30%. Inverse Laplace transform of 3He longitudinal magnetization recovery curve has been carried out, thus distribution of relaxation times T1 has been obtained.

cond-mat.other↗

arXiv2010

Orbital glass and spin glass states of 3He-A in aerogel

Glass states of superfluid A-like phase of 3He in aerogel induced by random orientations of aerogel strands are investigated theoretically and experimentally. In anisotropic aerogel with stretching deformation two glass phases are observed. Both phases represent the anisotropic glass of the orbital ferromagnetic vector l -- the orbital glass (OG). The phases differ by the spin structure: the spin nematic vector d can be either in the ordered spin nematic (SN) state or in the disordered spin-glass (SG) state. The first phase (OG-SN) is formed under conventional cooling from normal 3He. The second phase (OG-SG) is metastable, being obtained by cooling through the superfluid transition temperature, when large enough resonant continuous radio-frequency excitation are applied. NMR signature of different phases allows us to measure the parameter of the global anisotropy of the orbital glass induced by deformation.

cond-mat.dis-nn↗