Characterization of RScO3, LuFe2O4 and M72Fe30 based molecules by x-ray spectroscopic techniques

• Main Author: Derks, Christine
• Other Authors: apl. Prof. Dr. Manfred Neumann
• Format: Doctoral Thesis
• Language: English
• Published: 2013
• Subjects: Röntgenspektroskopie; Seltene Erden; Polyoxometalate; Multiferroics; 33.61 - Festkörperphysik; 33.05 - Experimentalphysik; ddc:530
• Online Access: https://repositorium.ub.uni-osnabrueck.de/handle/urn:nbn:de:gbv:700-2013040810750

This thesis gives a detailed overview about the electronic and magnetic structure of three different kinds of 3d-transition metal based materials with potential for possible future applications. The presented materials are a series of “high-k” rare-earth scandates, RScO3 (R=Pr, Nd, Sm, Eu, Gd, Tb and Dy), the muliferroic layered oxide LuFe2O4, and three iron-based magnetic polyoxometalates of the type {(M)M5}Fe30 (M =Mo,W). The samples are examined by several different x-ray spectroscopic techniques and complementary theoretical approaches, namely multiplet calculations and first principles electronic structure calculations, respectively. The occupied electronic states are determined by photoelectron spectroscopy (XPS) and x-ray emission spectroscopy (XES). The unoccupied states are investigated by x-ray absorption spectroscopy (XAS). X-ray magnetic circular dichroim (XMCD) is used to get the element specific magnetic moment of the materials, and these results are compared to SQUID measurements.