Magnetic polarization of the americium $J=0$ ground state in AmFe${}_2$

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 $⟨J_z⟩$ = 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 $⟨T_z⟩$ can be determined directly; we discuss the progression of the latter across the actinide series.

6 pages, 5 figures to be published in Physical Review Letters (2015)

References in corpus (3)

• Nature of the 5f states in actinide metals
• Electronic structure and non-magnetic character of $\delta$-Pu-Am alloys
• Low temperature magnetic properties of NpNi${}_5$

Cited by in corpus (4)

• Synchrotron Radiation Techniques and their Application to Actinide Materials
• Assessment of the U and Co magnetic moments in UCoGe by X-ray magnetic circular dichroism
• Probing magnetism in the vortex phase of PuCoGa${}_5$ by X-ray magnetic circular dichroism
• Evidence of The Anomalous Fluctuating Magnetic State by Pressure Driven 4f Valence Change in EuNiGe${}_3$