Numéro
J. Physique Lett.
Volume 45, Numéro 8, avril 1984
Page(s) 373 - 378
DOI https://doi.org/10.1051/jphyslet:01984004508037300
J. Physique Lett. 45, 373-378 (1984)
DOI: 10.1051/jphyslet:01984004508037300

Neutron diffraction study on U0.5Np0.5O2 at low temperatures

A. Tabuteau1, M. Pagés1, A. Boeuf2, J. Rebizant3, L. Manes3, R. Caciuffo4 et F. Rustichelli4

1  Institut Curie, Section de Physique et Chimie, 11, rue Pierre et Marie Curie, 75231 Paris Cedex 05, France
2  Institut Laue-Langevin, Grenoble, France, and Commission of the European Communities, J.R.C. Ispra, Italy
3  Commission of the European Communities, J.R.C. Karlsruhe, F.R.G.
4  Università di Ancona, Italy


Abstract
The results of a neutron diffraction study on U0.5Np0.5 O2 solid solution at low temperature are reported. Below T = 12 K the solid solution is magnetically ordered with a magnetic structure different from that of the UO2 low temperature phase. The temperature dependence of the observed magnetic line width could suggest an eventual short range nature of the magnetic order. The neutron diffraction results are supported by Mössbauer spectroscopy measurements.


Résumé
La solution solide U0,5Np0,5O2 s'ordonne en dessous de 12 K et présente une structure magnétique différente de celle observée pour UO2. L'évolution de la largeur de la raie magnétique en fonction de la température pourrait suggérer un ordre magnétique à courte distance.

PACS
7525 - Spin arrangements in magnetically ordered materials.
7680 - Mossbauer effect: other gamma ray spectroscopy in condensed matter.

Key words
magnetic structure -- Mossbauer effect -- neptunium compounds -- neutron diffraction examination of materials -- uranium compounds -- U sub 0.5 Np sub 0.5 O sub 2 -- low temperatures -- neutron diffraction -- solid solution -- magnetically ordered -- magnetic structure -- temperature dependence -- magnetic line width -- Mossbauer spectroscopy