Neutron-Diffraction Study of Antiferromagnetism in UO2

B. C. Frazer, G. Shirane, D. E. Cox, and C. E. Olsen
Phys. Rev. 140, A1448 – Published 15 November 1965
PDFExport Citation

Abstract

Antiferromagnetism in UO2 has been investigated in a detailed single-crystal neutron-diffraction study. Work on this material was prompted by a general interest in unpaired 5f and 6d electron distributions for different valence states of uranium in simple compounds. The form factor determined in the present case indicates a 5f2 electronic configuration with an effective moment slightly less than 1.8μB for the U4+ ion. The magnetic ordering of the first kind, reported earlier by Henshaw and Brockhouse, is confirmed, but their proposed [111] orientation for the magnetization axis is not. The axis is found to be within the alternating ferromagnetic sheets. In the course of the diffraction study it was found that the paramagnetic-to-antiferromagnetic transition is an unusually sharp one, especially for such a simple magnetic system. Accordingly, the temperature dependence of magnetic neutron intensities was investigated through the Néel point. From the sharpness of the transition (50% of the magnetization is established within 0.03° below the Néel temperature), and the absence of a critical scattering peak, it is concluded that the transition is of the first order.

  • Received 30 June 1965

DOI:https://doi.org/10.1103/PhysRev.140.A1448

©1965 American Physical Society

Authors & Affiliations

B. C. Frazer, G. Shirane, and D. E. Cox

  • Brookhaven National Laboratory, Upton, New York

C. E. Olsen

  • Los Alamos Scientific Laboratory, Los Alamos, New Mexico

References (Subscription Required)

Click to Expand
Issue

Vol. 140, Iss. 4A — November 1965

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Journals Archive

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×