Abstract: Complexes containing rare-earth ions attract great attention for their technological applications ranging from spintronic devices to quantum information science. While charged rare-earth coordination complexes are ubiquitous in solution, they are challenging to form on material surfaces that would allow investigations for potential solid-state applications. In this talk, we will present the formation and atomically precise manipulation of rare-earth complexes on solid surfaces [1,2]. Atomic scale manipulations and characterization of individual rare-earth complexes are performed with scanning tunneling microscopy and synchrotron X-ray scanning tunneling microscopy. I will also present our breakthrough research, where X-ray spectroscopy has been successfully performed for the first time to simultaneously characterize the elemental, chemical, and magnetic properties of just one rare earth atom [3].
References: [1] D. Trainer, A. T. Lee, S. Sarkar, V. Singh, X. Cheng, N. K. Dandu, K. Z. Latt, S. Wang, T. M. Ajayi, S. Premarathna, D. Facemyer, L. A. Curtiss, S. E. Ulloa, A. T. Ngo, E. Masson, & S. W. Hla. Adv. Sci. 2308813 (2024). [2] T.M. Ajayi, V. Singh, K.Z. Latt, S. Sarkar, X. Cheng, S. Premarathna, N.K. Dandu, S. Wang, F. Movahedifar, S. Wieghold, N. Shirato, V. Rose, L.A. Curtiss, A.T. Ngo, E. Masson, and S.-W. Hla. Nat. Commun. 13, 6305 (2022). [3] T.M. Ajayi, N. Shirato, T. Rojas, S. Wieghold, X. Cheng, K. Z. Latt, D. J. Trainer, N. K. Dandu, Y. Li, S. Premarathna, S. Sarkar, D. Rosenmann, Y. Liu, N. Kyritsakas, S. Wang, E. Masson, V. Rose, X. Li, A. T. Ngo, & S.-W. Hla. Nature 618, 69-73 (2023).
Bio: Saw Wai Hla is a physicist at the Center for Nanoscale Materials in Argonne National Laboratory and a professor in the Department of Physics & Astronomy at Ohio University. Since the beginning of 2023, he was also elected as the director of Nanoscale and Quantum Phenomena Institute of Ohio University. He has served as a director of the Condensed Matter and Surface Program at Ohio University (2015-2018) and as a group leader of the Electronic and Magnetic Materials and Devices Group (2011-2015) and Quantum and Energy Materials Group (2016-2019) in the Center for Nanoscale Materials at Argonne National laboratory. He received a B.Sc. (Hons) and M.Sc. in physics from Yangon University, Myanmar, in 1990, a DICTP (MS equivalent) in condensed matter theory from ICTP, Trieste, Italy, in 1993, and a Ph.D. in experimental physics from the University of Ljubljana, Slovenia, in 1997. After postdoctoral appointments at the ELETTRA synchrotron light source in Trieste, Italy (1997-1998), and Freie University and Paul Drude Institute for Solid State Electronics, Berlin, in Germany (1998-2001), Dr. Hla joined Ohio University as an assistant professor of physics in 2001. In 2005, Dr. Hla was promoted to associate professor with tenure and in 2011 to full professor. In 2011, he joined Argonne as a dual appointment with OU. Dr. Hla also has been a visiting professor at the University of Hamburg, Germany (Roland Wiesendanger group, 2008-2009) and in the Department of Chemistry at the Universite Paul Sabatier in France (2010) during his sabbatical periods. He is a world-leading researcher in the field of atomic and molecular manipulation using low-temperature scanning tunneling microscopy and synchrotron x-ray studies of individual atoms. His research focuses on nano and quantum properties of materials, in particular molecular machines, and rare-earth molecular systems.
In-Person Location: Bldg. 440, A105/A106
Zoom Link: https://argonne.zoomgov.com/j/1613912289