Preliminary observation of a nuclear antiferromagnetic structure by neutron diffraction
Creators
- 1. CEA Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Service de Physique du Solide et de Resonance Magnetique
Description
A nuclear antiferromagnetic structure has been produced in a single crystal of lithium hydride, by means of a dynamic polarization followed by an adiabatic demagnetization in the rotating frame (ADRF) of the two nuclear species 7Li and 1H. The existence of this structure has been demonstrated through the observation of the antiferromagnetic superstructure neutron Bragg reflexion 110. The nature of this reflexion is identified unambiguously by the appearance of a neutron signal immediately following the ADRF. The signal related to the long range nuclear antiferromagnetic order disappears after 30 min., a duration comparable to the dipolar spin-lattice relaxation time. As expected, a reduced NMR signal lingers for some further time, because of the short range paramagnetic correlations between the nuclear spins
Abstract (French)
Une structure antiferromagnetique nucleaire a ete produite dans un cristal d'hydrure de lithium par polarisation dynamique, suivie de desaimantation adiabatique dans le referentiel tournant, des deux especes nucleaires 7Li et 1H. Cette structure a ete mise en evidence par l'observation d'une reflexion neutronique de surstructure antiferromagnetique 110. Cette reflexion est identifiee sans equivoque par l'apparition d'un signal neutronique aussitot apres la desaimantation nucleaire. Ce signal indicatif de l'ordre antiferromagnetique nucleaire a longue distance disparait au bout de 30 mm, une duree comparable au temps de relaxation dipolaire. Il subsiste toutefois encore a ce moment, conformement aux previsions, un signal reduit de RMN, indicatif de correlations paramagnetiques a courte distanceAdditional details
Additional titles
- Original title (French)
- Premiere observation d'une structure antiferromagnetique nucleaire par diffraction neutronique
Publishing Information
- Journal Title
- C. R. Hebd. Seances Acad. Sci., Ser. B
- Journal Volume
- 286
- Journal Issue
- 22
- Series
- C. R. Hebd. Seances Acad. Sci., Ser. B.
- Journal Page Range
- 311-314
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 10464114
- Subject category
- S75: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY;
- Descriptors DEI
- ADIABATIC DEMAGNETIZATION; ANTIFERROMAGNETISM; LITHIUM FLUORIDES; NEUTRON DIFFRACTION
- Descriptors DEC
- ALKALI METAL COMPOUNDS; COHERENT SCATTERING; DEMAGNETIZATION; DIFFRACTION; FLUORIDES; FLUORINE COMPOUNDS; HALIDES; HALOGEN COMPOUNDS; LITHIUM COMPOUNDS; MAGNETISM; SCATTERING