Dichroism magnetic

In a magnetic material, here a 3d ferromagnetic metal (like Fe), the polarization creates a magnetic field which causes a splitting of the j — 3/2 and 1/2 levels into sublevels, ruj = —3/2,—1/2,1/2,3/2 and mj = 1/2, —1/2, as illustrated in Fig. 14. According to the dipole selection rules transitions are allowed with right/left circularly polarized light between states with Am = +1/ — 1. Such transitions are shown as arrows in Fig. 

The right-hand side of the figure is a sketch of a (broadened) difference signal. [150] 

A sum rule derived by Thole et al. [151], and also by Altarelli,[152] states that (approximately) the integral of the circular dichroism signal from two spin-orbit partners of a core edge is related to the orbital moment  

In Ref. [153] it was found that the angular-momentum rule eq. (71) for Fe, Co, and Ni holds within 10% but that the spin rule, eq. (72), in particular for Ni has substantial errors. With 

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MAGNETIC DICHROISM IN VALENCE BAND X-RAY PHOTO EMISSION SPECTROSCOPY... 

Thole BT, van der Laan G (1991) Origin of spin polarization and magnetic dichroism in corelevel photoemission. Phys Rev Lett 67 3306... 

The most interesting case is photoemission of 4/ electrons in the rare earths as noted in the previous section, because of the collapsed nature of the 4/ orbitals, the photoemission spectrum can be interpreted completely even in the solid by atomic multiplet theory, and this applies also to magnetic circular dichroism. Thole and van der Laan [642] have derived sum rules for magnetic dichroism in rare-earth 4/ photoemission. They have shown that the integrated intensity is simply the sum over each sublevel of its occupation number times the total transition probability from that sublevel to the continuum shell. Polarisation effects in the 4/ photoemission spectra of rare earths are very large, and this tool based on quasiatomic analysis is of considerable significance it provides a new... 

HOUSSiER, c. and saver, k. (1970). Circular dichroism and magnetic dichroism of the chlorophyll and photochlorophyll pigments. J. Am. Chem. Soc. 92, 781-782. 

Magnetic circular and Unear dichroism in the angular distribution of photoelectrons (MCDAD and MLDAD) are due to the interaction between spin-orbit coupling and exchange splitting. Thus, the intensity distribution of the emitted photoelectrons becomes modified as a ftmction of the macroscopic magnetization direction and the photon spin. The magnetic dichroism is an effect which requires a chirality of the system. 

As discussed in Sect. 5.1.2 it turned out that magnetic dichroism experiments are able to determine magnetic properties. In the following it will be shown that this experimental technique also allows the investigation of the magnetic behavior of adsorbate atoms on ferromagnetic surfaces [93]. 

Especially, I would like to thank Prof. Dr. Matthias Bode (now at the University of Wurzburg) for his introduction and continuous help on the field of scanning tunneling microscopy and spectroscopy. Further, I thank Prof. Dr. Astrid Pundt from the University of Gottingen for her fruitful discussions on the influence of hydrogen atoms in solids. Last but not least I thank PD Dr. Joachim Bansmann (now at Ulm University) for the close collaboration on magnetic dichroism studies. 

MDAD Magnetic dichroism in the angular distribution of photoelectrons MDS Metastable de-excitation spectroscopy... 

Yamamoto, D. Studies on the magnetic dichroism of dye-gelatin films. III. Magnetic dichroism of dye gelatin films excited by light. Bull. Chem. Soc. Jpn. 1951, 24, 211-214. 

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