Synchrotron x-ray scattering of magnetic and electronic structure of UN and U2N3 epitaxial films
| Autor: | E. Lawrence Bright, Ross S Springell, D. G. Porter, Sean P. Collins, G. H. Lander |
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| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | Physical Review B. 100 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | We examine the magnetic ordering of UN and of a closely related nitride, ${\mathrm{U}}_{2}{\mathrm{N}}_{3}$, by preparing thin epitaxial films and using synchrotron x-ray techniques. The magnetic configuration and subsequent coupling to the lattice are key features of the electronic structure. The well-known antiferromagnetic (AF) ordering of UN is confirmed, but the expected accompanying distortion at ${\mathrm{T}}_{N}$ is not observed. Instead, we propose that the strong magnetoelastic interaction below ${\mathrm{T}}_{N}$ causes substantial changes in the strain in the sample being measured. These strains vary as a function of the sample form. As a consequence, the accepted AF configuration of UN may be incorrect. In the case of cubic $\ensuremath{\alpha}\ensuremath{-}{\mathrm{U}}_{2}{\mathrm{N}}_{3}$, no single crystals have been previously prepared, and we have determined the AF ordering wave vector. The AF ${\mathrm{T}}_{N}$ is close to that previously reported. In addition, resonant diffraction methods have identified an aspherical quadrupolar charge contribution in ${\mathrm{U}}_{2}{\mathrm{N}}_{3}$ involving the $5f$ electrons. |
| Databáze: | OpenAIRE |
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