NUCLEAR MAGNETIC RESONANCE IN SOLIDS

The methodological textbook for laboratory work "Nuclear magnetic resonance in solids" for the master course students recounts the basics of the nuclear magnetic resonance theory in diamagnetic insulating crystals and the experimental principles of nuclear magnetic resonance signals detection by continuous wave and pulsed methods, and also a calculation procedure of the nuclear magnetic resonance line shape as obtained in experiment. The textbook gives a short description and operation principle of laboratory NMR setups.9

High-T c spin superfluidity in antiferromagnets

We report the observation of the unusual behavior of induction decay signals in antiferromagnetic monocrystals with Suhl-Nakamura interactions. The signals show the formation of the Bose-Einstein condensation (BEC) of magnons and the existence of spin supercurrent, in complete analogy with the spin superfluidity in the superfluid He3 and the atomic BEC of quantum gases. In the experiments described here, the temperature of the magnon BEC is a thousand times larger than in the superfluid He3. It opens a possibility to apply the spin supercurrent for various magnetic spintronics applications. © 2012 American Physical Society

Nuclear pseudoquadrupole resonance of 141Pr in Van Vleck paramagnet PrF3

Nuclear pseudoquadrupole resonance of 141Pr in Van Vleck paramagnet PrF3 has been observed in singlecrystal and micro- and nanopowder samples at a temperature of 4.2 K. The spectra of nuclear pseudoquadrupole resonance of 141Pr, as well as the spin-spin and spin-lattice relaxation parameters, have been obtained. The parameters of the nuclear spin Hamiltonian have been determined. It has been found that the parameters of the crystal electric field in nanocrystals differ strongly from those in microcrystals. © 2011 Pleiades Publishing, Ltd

Application of cryogenic technologies for NMR logging tool

The development of heavy oil and bitumen deposits is becoming an actual problem in last years. In this paper the authors propose to use cryogenic technologies for improving the sensitivity of nuclear magnetic resonance logging tool. Particularly, it is proposed to use a magnetic system made of a high temperature superconductor. The low temperature of the magnetic system is provided by the thermal contact with cryocapacitor, which is made of a material with a high specific heat at low temperatures. Experimental data are presented

The Calcium Carbonate Geological Samples Study by ³He NMR

© 2017 Springer-Verlag WienGeological samples of calcium carbonates (CaCO3) were investigated by 3He NMR, nitrogen porosimetry, X-ray diffraction and electron microscopy methods. The integral porosity of the samples was obtained by 3He nuclear magnetic resonance method and compared with nitrogen adsorption isotherms data. The advantages of 3He porometry method are discussed

Low temperature adsorption of 3He on silica aerogel surface and its influence on 3He spin kinetics

Significant influence of the aerogel surface heterogeneity on the processes of 3He nuclear magnetic relaxation at temperatures 1.5 - 4.2 K is discovered. This influence appears, for instance, in differences of the 3He T 1 relaxation times for small portion of 3He, adsorbed at different temperatures. Binding energy data of 3He and distributions of this energy in two types of aerogel were obtained experimentally. Adsorbed 3He molecules with binding energies 60 - 250 K play supreme role in processes of nuclear magnetic relaxation of gaseous and liquid 3He in aerogel

Discovery of the classical Bose-Einstein condensation of magnons in solid antiferromagnets

Results of experiments in which the Bose-Einstein condensate of magnons is created in the CsMnF 3 easy-plane antiferromagnet in a system with coupled nuclear-electron precession with dynamical frequency shift are presented. This condensate is similar to the Bose-Einstein condensate of magnons in superfluid 3He-A in aerogel. © 2011 Pleiades Publishing, Ltd

Atomic type magnon Bose-Einstein condensation in antiferromagnet

The Spin Supercurrent and Bose-Einstein condensation of magnons, similar to an atomic BEC, was observed in 1984 in superfluid 3He-B The same phenomena should exist in solid magnetic systems. We describe here the first observation of magnon BEC in solid easy plain antiferromagnet CsMnF3. We have observed magnon BEC on a mode of coupled Nuclear-Electron precession. The dynamical properties of this mode have many similarities with NMR of superfluid 3He-A The frequency changes with deflection of nuclear magnetization. Furthermore, the involvement of electron ordered subsystem gives the magnon-magnon interaction, spin waves and spin supercurrent, while the nuclear subsystem gives the relatively long time of relaxation