Surface-Enhanced Nonreciprocal Response in Iron Garnets

Iron garnets play a significant role in optical isolator devices for telecommunications
applications. Recent studies in iron garnet media have revealed a 7-fold increase in
the Faraday rotation response within 2 nm of the surface¹. We will present a surface-
reconstruction analysis of Bi-substituted magneto-optic films conducted via
scanning-transmission-electron microscopy (STEM). Differences found between the
bulk and surface atomic structures will be discussed². Analysis of
electronic absorption and magnetic circular dichroism (XMCD) spectra in total
fluorescence yield (TFY) and total electron yield (TEY) for 2p to 3d transitions in Fe 3+
ions were performed and will be discussed.
1. M. Levy, O. V. Borovkova, C. Sheidler, B. Blasiola, D. Karki, F. Jomard, M. A.
Kozhaev, E. Popova, N. Keller, V. I. Belotelov, “Faraday rotation in iron garnet films
beyond elemental substitutions,” Optica 6 (5), 642-645 (2019).
2. S.S. Dash, P. Mukherjee, D. Haskel, R.A. Rosenberg, M. Levy, “Boosting optical
nonreciprocity: Surface reconstruction in iron garnets,” Optica 7 (9), 1038-1044 (2020).