Estimating the Orientation of 4f Magnetic Moments by Classical Photoemission
Dmitry Yu. Usachov, Д. А. Глазкова, А. В. Тарасов, Susanne Schulz, G. Poelchen, Kirill A. Bokai, O. Yu. Vilkov, Pavel Dudin, K. Kummer, Kristin Kliemt, C. Krellner, D. V. Vyalikh
Abstract
To use efficiently the magnetic functionalities emerging at the surfaces or interfaces of novel lanthanides-based materials, there is a need for complementary methods to probe the atomic-layer resolved magnetic properties. Here, we show that 4f photoelectron spectroscopy is highly sensitive to the collective orientation of 4f magnetic moments and, thus, a powerful tool for characterizing the related properties. To demonstrate this, we present the results of systematic study of a family of layered crystalline 4f-materials, which are crystallized in the body-centered tetragonal ThCr2Si2 structure. Analysis of 4f spectra indicates that the 4f moments at the surface experience a strong reorientation with respect to the bulk, caused by changes of the crystal-electric field. The presented database of the computed 4f spectra for all trivalent rare-earth ions in their different MJ states will facilitate the estimation of the orientation of the 4f magnetic moments in the layered 4f-systems for efficient control of their magnetic properties.