Sign of nuclear electric quadrupole coupling constants in solids from γ-ray anisotropy measurements after capture of polarized neutrons

verfasst von: D. Dubbers, H. Ackermann, M. Grupp, P. Heitjans, H. J. Stöckmann
Abstract: An experimental method is presented which allows the determination of the sign of nuclear electric quadrupole interactions in solids. Activated target nuclei with a purely dipolar spin polarization are produced by capture of polarized thermal neutrons. The quadrupole coupling of the nuclei to the electric field gradient tensor in the target crystal converts this (dipolar) polarization partly into a (quadrupolar) alignment, which can be measured by the anisotropy of the γ-ray emission in a succeeding nuclear transition. The sign of the alignment created in this reorientation process depends on the sign of the electric quadrupole interaction. The reorientation effect can be enhanced by selective induction of nuclear magnetic resonance transitions. The method has been applied to measure the sign of the crystal electric field gradient (efg) in tetragonal MgF₂. Further, the sign of an efg in cubic CaF₂ originating from a¹⁹F interstitial adjacent to the activated²⁰F probe nucleus has been determined. The method is in principle applicable to a considerable number of nuclides.
Externe Organisation(en): Ruprecht-Karls-Universität Heidelberg
Institut Laue-Langevin
Typ: Artikel
Journal: Zeitschrift für Physik B Condensed Matter and Quanta
Band: 25
Seiten: 363-368
Anzahl der Seiten: 6
ISSN: 0340-224X
Publikationsdatum: 12.1976
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Elektronische, optische und magnetische Materialien, Physik der kondensierten Materie
Elektronische Version(en): https://doi.org/10.1007/BF01315252 (Zugang: Unbekannt)

BibTeX

@article{7e68177d391f469a862923c2e203a342,
title = "Sign of nuclear electric quadrupole coupling constants in solids from γ-ray anisotropy measurements after capture of polarized neutrons",
abstract = "An experimental method is presented which allows the determination of the sign of nuclear electric quadrupole interactions in solids. Activated target nuclei with a purely dipolar spin polarization are produced by capture of polarized thermal neutrons. The quadrupole coupling of the nuclei to the electric field gradient tensor in the target crystal converts this (dipolar) polarization partly into a (quadrupolar) alignment, which can be measured by the anisotropy of the γ-ray emission in a succeeding nuclear transition. The sign of the alignment created in this reorientation process depends on the sign of the electric quadrupole interaction. The reorientation effect can be enhanced by selective induction of nuclear magnetic resonance transitions. The method has been applied to measure the sign of the crystal electric field gradient (efg) in tetragonal MgF2. Further, the sign of an efg in cubic CaF2 originating from a19F interstitial adjacent to the activated20F probe nucleus has been determined. The method is in principle applicable to a considerable number of nuclides.",
author = "D. Dubbers and H. Ackermann and M. Grupp and P. Heitjans and St{\"o}ckmann, {H. J.}",
year = "1976",
month = dec,
doi = "10.1007/BF01315252",
language = "English",
volume = "25",
pages = "363--368",
journal = "Zeitschrift f{\"u}r Physik B Condensed Matter and Quanta",
issn = "0340-224X",
publisher = "Springer New York",
number = "4",
}