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arXiv · 1502.05604

Magnetic polarization of the americium $J = 0$ ground state in AmFe$_{2}$

N. Magnani·R. Caciuffo·F. Wilhelm·E. Colineau·R. Eloirdi·J. -C. Griveau·J. Rusz·P. M. Oppeneer·A. Rogalev·G. H. Lander
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Abstract

Trivalent americium has a non-magnetic ($J$ = 0) ground state arising from the cancelation of the orbital and spin moments. However, magnetism can be induced by a large molecular field if Am$^{3+}$ is embedded in a ferromagnetic matrix. Using the technique of x-ray magnetic circular dichroism, we show that this is the case in AmFe$_2$. Since $\langle J_z \rangle$ = 0, the spin component is exactly twice as large as the orbital one, the total Am moment is opposite to that of Fe, and the magnetic dipole operator $\langle T_{z} \rangle$ can be determined directly; we discuss the progression of the latter across the actinide series.

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N. Magnani, R. Caciuffo, F. Wilhelm, E. Colineau, R. Eloirdi, J. -C. Griveau, J. Rusz, P. M. Oppeneer, A. Rogalev, G. H. Lander. 2015-02-19. Magnetic polarization of the americium $J = 0$ ground state in AmFe$_{2}$. https://doi.org/10.1103/physrevlett.114.097203

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