With synchrotron radiation description

The aim of this chapter is to report on recent advances in the in situ Mossbauer spectroscopy with synchrotron radiation on thin films that became possible due to the instrumentation developments at the nuclear resonance beamline ID 18 of the ESRF. After a detailed description of the beamline and of the UHV system for in situ experiments, a brief introduction into the basic NRS techniques is given. Finally, the application of these techniques to investigate magnetic, diffusion, and lattice dynamics phenomena in ultrathin epitaxial Fe films deposited on a W(l 10) substrate is presented and discussed. 

In Chapters I and 2, an introduction is made to the synchrotron Mossbauer spectroscopy with examples. Examples include the/ns/tu Mossbauer spectroscopy with synchrotron radiation on thin films and the study of deep-earth minerals. Investigations of in-beam Mossbauer spectroscopy using a Mn beam at the RIKEN RIBF is presented in Chapter 3. This chapter demonstrates innovative experimental setup for online Mossbauer spectroscopy using the thermal neutron capture reaction, Fe (n, y) Fe. The Mossbauer spectroscopy of radionuclides is described in Chapters 4-7. Chapter 4 gives full description of the latest analysis results of lanthanides Eu and Gd) Mossbauer structure and powder X-ray diffraction (XRD) lattice parameter (oq) data of defect fluorite (DF) oxides with the new defect crystal chemistry (DCC) Oq model. Chapter 5 reviews the Np Mossbauer and magnetic study of neptunyl(+l) complexes, while Chapter 6 describes the Mossbauer spectroscopy of organic complexes of europium and dysprosium. Mossbauer spectroscopy is presented in Chapter 7. There are three chapters on spin-state switching/spin-crossover phenomena (Chapter 8-10). Examples in these chapters are mainly on iron compounds, such as iron(lll) porphyrins. The use of Mossbauer spectroscopy of physical properties of Sn(ll) is discussed in Chapter I I. 

A non exhaustive description of the history of X-ray Absorption Spectroscopy (XAS) can be found in Ref. 1. The modem EXAFS (Extended X-ray Absorption Fine Structure) technique began in the early seventies of the last century. It corresponds to the concomitance of both theoretical and experimental developments. Between 1969 and 1975, Stem, Sayers and Lytle succeeded in interpreting theoretically the X-ray Absorption Structures observed above an absorption edge [2], while during the same period, the advent of synchrotron radiation (SR) sources reduced drastically the acquisition time of a spectrum if compared to data obtained with conventional X-ray tubes. XAS provides essential information about the local atomic geometry and the electronic and chemical state of a specific atom, for almost any element of the periodic table (Z>5). This prime tool for... 

The study of these systems have become possible thanks to the development of various preparation routes, from sophisticated routes for the preparation of model materials with controlled nanostructures to industrial routes for the production of large quantity of materials. It has benefited as well from the development of new experimental techniques, allowing the properties of matter to be quantitatively examined at the nanometre scale. These include Hall micro-probe [3] or micro-SQUID magnetometry [4], XMCD at synchrotron radiation facilities [5] and scanning probe microscopes [6]. This is not the topic of this chapter to describe in detail these various techniques. They are only quoted in the following sections. The reader may find in the associated references the detailed technical descriptions that he may need. 

Although most suitable for use with lasers, Thermionic diodes have also been successfully applied to synchrotron radiation studies by using wiggler magnets to enhance the intensity of the beam [390]. Last but not least, one should mention the important category of atomic beam experiments, complemented by the techniques of photoelectron and photoion spectroscopy. All these techniques are suitable for the experimental study of interacting resonances. We turn now to their theoretical description, which will be illustrated by experimental examples. 

A review of these disparate but related investigations is presented beginning with a description of the use of time-resolved X-ray diffraction (TRXRD) to study lipid phase transition kinetics and mechanism in Sect. 1. It is the enormous intrinsic intensity of synchrotron radiation that enables TRXRD measurements to be made. However, this advantage brings with it the hazards of radiation damage. This critical issue is addressed in Sect. 2 along with recommendations for minimizing the effect. 

Additionally, information on quantum mechanical quantities are usually obtained with a more or less larger experimental or theoretical effort. Being in contrast, the theoretical description of the latter type of angle resolving photoemission experiments as well as the experimental procedure are relatively simple. This method is suitable to be carried out in a laboratory because it does not need a sophisticated experimental setup as synchrotron radiation sources. It may therefore play an important role for a proceeding understanding of the photoemission process. 

In the following, a description of an improved Kratky-camera [73] will be discussed together with an extended discussion of the treatment of data. This device is capable of measuring latex particles up to a diameter of 200 nm and reaches the q-range provided by SAXS-cameras which work in point collimation and use synchrotron radiation (cf. below [73]). 

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