Resonant Inelastic X-ray Scattering (RIXS)
 is an X-ray in, X-ray out technique that enables one to study the 
dispersion of excitations in solids. In this thesis, we investigated how
 various elementary excitations of transition metal oxides show up in 
RIXS spectra.

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Resonant Inelastic X-ray Scattering Studies of Elementary Excitations

https://www.anorg.chem.uu.nl/CTM4XAS/Papers/science.pdf

The CTM4XAS program for EELS and XAS spectral shape analysis of transition metal L edges

A conductive polymer is developed for solving the long-standing volume change issue in lithium battery electrodes. A combination of synthesis, spectroscopy and simulation techniques tailors the electronic structure of the polymer to enable in situ lithium doping. Composite anodes based on this polymer and commercial Si particles exhibit 2100 mAh g -1 in Si after 650 cycles without any conductive additive. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

/pdf/polymers-with-tailored-electronic-structure-for-high-38eh17sbop.pdf

Polymers with Tailored Electronic Structure for High Capacity Lithium Battery Electrodes

A novel air-stable sodium iron hexacyanoferrate (R-Na1.92Fe[Fe(CN)6]) with rhombohedral structure is demonstrated to be a scalable, low-cost cathode material for sodium-ion batteries exhibiting high capacity, long cycle life, and good rate capability. The cycling mechanism of the iron redox is clarified and understood through synchrotron-based soft X-ray absorption spectroscopy, which also reveals the correlation between the physical properties and the cell performance of this novel material. More importantly, successful preparation of a dehydrated iron hexacyanoferrate with high sodium-ion concentration enables the fabrication of a discharged sodium-ion battery with a non-sodium metal anode, and the manufacturing feasibility of low cost sodium-ion batteries with existing lithium-ion battery infrastructures has been tested.

Rhombohedral prussian white as cathode for rechargeable sodium-ion batteries.

Crucial to many light-driven processes in transition metal complexes is the absorption and dissipation of energy by 3d electrons. But a detailed understanding of such non-equilibrium excited-state dynamics and their interplay with structural changes is challenging: a multitude of excited states and possible transitions result in phenomena too complex to unravel when faced with the indirect sensitivity of optical spectroscopy to spin dynamics and the flux limitations of ultrafast X-ray sources. Such a situation exists for archetypal polypyridyl iron complexes, such as [Fe(2,2'-bipyridine)3](2+), where the excited-state charge and spin dynamics involved in the transition from a low- to a high-spin state (spin crossover) have long been a source of interest and controversy. Here we demonstrate that femtosecond resolution X-ray fluorescence spectroscopy, with its sensitivity to spin state, can elucidate the spin crossover dynamics of [Fe(2,2'-bipyridine)3](2+) on photoinduced metal-to-ligand charge transfer excitation. We are able to track the charge and spin dynamics, and establish the critical role of intermediate spin states in the crossover mechanism. We anticipate that these capabilities will make our method a valuable tool for mapping in unprecedented detail the fundamental electronic excited-state dynamics that underpin many useful light-triggered molecular phenomena involving 3d transition metal complexes.

/pdf/tracking-excited-state-charge-and-spin-dynamics-in-iron-4sglc4c6t2.pdf

Tracking excited-state charge and spin dynamics in iron coordination complexes

INTRODUCTION FUNDAMENTAL ASPECTS OF CORE LEVEL SPECTROSCOPIES Core holes Overview of core level spectroscopies Interaction of x-rays with matter Optical transition operators and x-ray absorption spectrum The interaction of electrons with matter X-ray sources Electron sources MANY-BODY CHARGE-TRANSFER EFFECTS IN XPS AND XAS Introduction Many-body charge-transfer effects in XPS General expressions of many-body effects General effects in XPS spectra Typical examples of XPS spectra Many-body charge-transfer effects in XAS Comparison of XPS and XAS CHARGE TRANSFER MULTIPLET THEORY Atomic multiplet theory Ligand field multiplet theory The charge transfer multiplet theory X-RAY PHOTOEMISSION SPECTROSCOPY Introduction Experimental aspects XPS of TM compounds XPS of RE compounds Resonant photoemission spectroscopy Hard XPS Resonant inverse photoemission spectroscopy Nonlocal screening effect in XPS Auger photoemission coincidence spectroscopy Spin polarization and magnetic dichroism in XPS X-RAY ABSORPTION SPECTROSCOPY Basics of XAS Experimental aspects The L2, 3 edges of 3d TM systems Other x-ray absorption spectra of the 3d TM systems X-ray absorption spectra of the 4d and 5d TM systems X-ray absorption spectra of the 4f RE and 5f actinide systems X-RAY MAGNETIC CIRCULAR DICHROISM Introduction XMCD effects in the L2, 3 edges of TM ions and compounds Sum rules XMCD effects in the K edges of transition metals XMCD effects in the M edges of rare earths XMCD effects in the L edges of rare earth systems Applications of XMCD RESONANT X-RAY EMISSION SPECTROSCOPY Introduction Rare earth compounds High Tc Cuprates and related materials Nickel and Cobalt compounds Iron and Manganese compounds Early transition metal compounds Electron spin states detected by RXES and NXES MCD in RXES of ferromagnetic systems APPENDICES Precise derivation of XPS formula Derivation of Eq. (88) in Chapter 3 Fundamental tensor theory Derivation of the orbital moment sum rule Theoretical test of the spin sum rule Calculations of XAS spectra with single electron excitation models REFERENCES INDEX

Akio Kotani

Papers

Core level spectroscopy of solids

X-Ray Absorption Spectroscopy

X-Ray Photoemission Spectroscopy