Magnetic behavior near the boundary of4fdelocalization in ferromagnetic CeRu2Ge2and paramagnetic CeRu

Abstract

X-ray absorption (XAS) and its magnetic circular dichroism (XMCD) were measured at the Ce M 4,5 absorption edges of ferromagnetic CeRu 2 Ge 2 and paramagnetic CeRu 2 Si 2 : both compounds are considered to be located near the boundary of delocalization of Ce 4f electrons. While the XAS line shape varies clearly reflecting the variation in the 4f delocalization, the line-shape variation in XMCD is hardly discernible under various conditions of temperature and magnetic field. The XAS line-shape variation can be explained as effects of the variations in the 4f occupation number and in the ratio of J = 7/2 states in the ground states, both of which are closely related to the 4f delocalization. The 4f delocalization also causes a decrease in the ratio of the orbital magnetic moment to the spin magnetic moment. The magnetic-field dependence of XAS suggests that the Ce 4f electrons retain a delocalized character across the metamagnetic transition in CeRu 2 Si 2 .

X-ray Magnetic Circular Dichroism Study of Ce0.5Gd0.5Ni

“…The existence of the Ni 3d magnetic moment is consistent with the previous XMCD results for GdNi [1]. The line shapes of the XAS and XMCD spectra are similar to those observed in the previous experiments for Gd-Ni systems [1,10] and Ce intermetallic compounds [9,11,12].…”

“…1. The existence of distinct Ce M 4,5 satellite structures suggests that the occupation number of the Ce 4f orbital is substantially lower than unity and the Ce 4f electrons of this system has considerable itinerant characters [9].…”

Electronic Structures of Ferromagnetic CeAgSb2: Soft X-ray Absorption, Magnetic Circular Dichroism, and Angle-Resolved Photoemission Spectroscopies

“…2, the spectral XMCD shape remains the same with increasing temperature. The multiplet features of the XMCD line shape are characteristic of γ-like Ce compounds [33][34][35] . Figure 5 shows the calculated XAS and XMCD spectra for 0 K with an infinitesimal exchange field and for 150 K with an external magnetic field of 10 T, which are in good agreement with our experimental spectra.…”

Fermi Surface Properties, Metamagnetic Transition and Quantum Phase Transition of CeRu2Si2 and Its Alloys Probed by the dHvA Effect

“…The X-ray absorption spectra measurements under magnetic fields indicate that the f 0 satellite intensity is almost unchanged above H m . 156 These observations indicate that significant hybridization between the f electron and the conduction electrons remains above H m . In these respects, the f electron state in the polarized state may have a significant itinerant character.…”