Studying the electronic structure of Gd-based MRI agents using resonant inelastic x-ray scattering spectroscopy
Yu-Cheng Shao1*, L. Andrew Wray2, Shih-Wen Huang3, Yi-Sheng Liu4, Shangfeng Yang5, Yi-De Chuang4, Jinghua Guo4, Way-Faung Pong1
1Department of Physics, Tamkang University, Tamsui, Sweden
2Department of Physics, New York University, New York, New York, USA
3MAX IV Laboratory, Lund, Sweden
4Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California, USA
5Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, China
* presenting author:Yu-Cheng Shao,
Gadolinium (Gd), when encaged in the endohedral fullerenes like C80, exhibits enhanced relaxation that can be used as a promising magnetic resonance imaging (MRI) agents[1,2]. However, the underlying spin dynamics in GdxSc3-x@C80 (x=1 and 2) remains unclear. Therefore, this investigation has been made on the first resonant inelastic x-ray scattering (RIXS) measurements at Gd N4,5-edge of these materials, which is strongly associated with Gd 4f electronic structure and the spin flip of 4f electrons[3,4]. It is very helpful to understand the reason of the enhanced relaxation. Compared to the reference Gd2O3, our RIXS data reveal broader spectral lineshape with noticeable energy shift in the endohedral fullerenes. Aided by atomic multiplet calculations, the energetic like spin exchange, Coulomb and spin-orbit couplings can be determined. The implication of these parameters to the enhanced relaxation will be discussed.

Keywords: Fullerene, resonant inelastic x-ray scattering, RIXS