تقرير
Low temperature magnetic properties of NpNi$_5$
| العنوان: | Low temperature magnetic properties of NpNi$_5$ |
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| المؤلفون: | Hen, A., Colineau, E., Eloirdi, R., Griveau, J. -C., Magnani, N., Wilhelm, F., Rogalev, A., Sanchez, J. -P., Shick, A. B., Halevy, I., Orion, I., Caciuffo, R. |
| المصدر: | Phys. Rev. B 90, 054408 (2014) |
| سنة النشر: | 2014 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Strongly Correlated Electrons |
| الوصف: | We present the result of an extended experimental characterization of the hexagonal intermetallic Haucke compound NpNi$_{5}$. By combining macroscopic and shell-specific techniques, we determine the 5$f$-shell occupation number $n_f$ close to 4 for the Np ions, together with orbital and spin components of the ordered moment in the ferromagnetic phase below T$_C$ = 16 K ($\mu_{S}$ = -1.88~$\mu_{B}$ and $\mu_{L}$ = 3.91~$\mu_{B}$). The apparent coexistence of ordered and disordered phases observed in the M\"{o}ssbauer spectra is explained in terms of slow relaxation between the components of a quasi-triplet ground state. The ratio between the expectation value of the magnetic dipole operator and the spin magnetic moment ($3\langle T_{z}\rangle/ \langle S_{z}\rangle$ = +1.43) is positive and large, suggesting a localized character of the 5$f$ electrons. The angular part of the spin-orbit coupling ($\langle\vec{\ell}\cdot\vec{s}\rangle$ = -5.55) is close to the value of -6.25 calculated for trivalent Np ions in intermediate coupling approximation. The results are discussed against the prediction of first-principle electronic structure calculations based on the spin-polarized local spin density approximation plus Hubbard interaction, and of a mean field model taking into account crystal field and exchange interactions. Comment: Accepted manuscript, to be published in Phys. Rev. B http://prb.aps.org |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevB.90.054408 |
| URL الوصول: | http://arxiv.org/abs/1407.6825 |
| رقم الأكسشن: | edsarx.1407.6825 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1103/PhysRevB.90.054408 |
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