Magnetic characterization

Information on the spin resolved band structure of ferromagnetic materials can directly be obtained from spin resolving photoelectron spectroscopy. Using polarized radiation spin integrating photoemission techniques already enable to have access to magnetic properties. An enhancement of the surface sensitivity can be achieved using neutral excited spin polarized atoms which move towards the sample and are de-excited by tunneling electrons from the surface with a subsequent emission of electrons. 

In the first part of this chapter it will be reported on spin dependent transport and surface magnetic properties of itinerant magnetic substrates, thin Fe(l 10) and Co(OOOl) films evaporated on W(110), which were investigated by these electron emission techniques. Subsequently, the behavior of adsorbates will be discussed from the point of view whether they change the properties of the surface and whether they feel the magnetism of the underlying substrate. This discussion will be carried out for the example of oxygen which adsorbs dissociatively on the above mentioned surfaces. 

A comprehensive overview on the fundamentals of magnetism and, especially, the magnetic behavior of low-dimensional systems can be found in [2]. 

Getzlaff, Surface Magnetism, Springer Tracts in Modem Physics, 240, 

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Vestal, C.R. and Zhang, Z.J. (2003) Synthesis and magnetic characterization of Mn and Co spinel ferrite—silica nanopartides with tunable magnetic core. Nano Letters, 3 (12), 1739-1743. 

Migowski, P., Teixeira, S.R., Machado, G., Alves, M.C.M., Geshev, J. and Dupont, J. (2007) Structural and magnetic characterization of Ni nanopartides synthesized in ionic liquids. Journal of Electron Spectroscopy and Related Phenomena, 156, 195—199. 

H. Mino and T. Ono, Applications of pulsed ELDOR-detected NMR measurements to studies of photosystem II Magnetic characterization of Yd tyrosine radical and Mn2+ bound to the high-affinity site, Appl. Magn. Reson., 2003, 23, 571. 

To our knowledge, there are less than 30 compounds based on radical-cations and M(dmit)2 systems (Table 2). Most of them contain divalent or monovalent M(dmit)2 units, and only a few of them have been structurally and magnetically characterized. Since they are not in a fractional oxidation state, they behave as insulators with low room-temperature conductivity. 

The Mo(III) d3-d3 complexes [CpMo(dithiolene)]2 are characterized by a single Mo—Mo bond, further stabilized by interaction with the n system of the dithiolene ligands. Indeed, the analogous complexes where the two dithiolene are replaced by four thiolate groups were found to oxidize more easily and salts of the cationic d3-d2 [CpMo(SMe)4MoCp]+ were even isolated and structurally and magnetically characterized [50]. 

Catalysts were prepared by impregnation of supports using Co2(CO)8 as a Co precursor. In situ magnetic characterization indicated that a mixed Co0 and Co2 + contributes to catalytic activity in the SRE reaction... 

Figure 6.42. Magnetic characterization of the hybrid material [BEDT-TIFJ3[MnCr(C204)3] (a) x (filled circles) and x" (open circles) measured at 110 Hz. (b) Plot of Sm versus magnetic field at 2 K. M and H represent and B, respectively. Reprinted with permission from Coronado et al, 2000. Copyright (2000) by the Nature Publishing Group.

Selected examples of oligonudear and extended chain complexes of nickel(II) which have been magnetically characterized are shown in Table 114. 

P2W15O56]12- anions have recently been structurally and magnetically characterized (Fang et al., 2005). 

NANOSCALE STRUCTURAL AND MAGNETIC CHARACTERIZATION USING ELECTRON MICROSCOPY... 

Nanoscale Structural and Magnetic Characterization Using Electron Microscopy... 

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