Electron-spin-dependent scattering

The use of polarised beams in collision studies has enabled experimentalists to perform very detailed tests of theoretical models, particularly with regard to the role of electron exchange and the spin—orbit interaction in spin-dependent scattering. We will now briefly discuss the role of these interactions before using the general density matrix method to describe the more general case where more than one mechanism may contribute to the spin-dependent effects. 

A polarised electron beam is made to strike a surface using an electron gun with a spin polarised electron source. The electrons reflected from the surface are energy analysed and then their spin polarisation is determined. This provides information regarding spin dependent scattering within the sample. 

In the Nordheim-Gorter rule (eq. (35)) the spin-dependent scattering processes of the conduction electrons are described by the third term ((Pmag/p)Smag)- According to the discussion in sect. 2.3 (see eq. (49)), > T ) = is proportional to T (if... 

In figs. 34 and 35 the temperature variation of the thermal conductvity of several compounds is given. Bauer et al. (1986) have shown that the contribution due to spin-dependent scattering processes to the thermal resistivity well above the Curie temperature is proportional to T. This part of the electronic thermal resistivity (denoted by scattering processes of the conduction electrons with... 

Spin-dependent scattering of polarized charge carriers (a scattering of conductivity electrons on phonons or impurities into corresponding available states of spin-polarized energy bands). 

In LB films not only the interaction of chromophores but also their orientation can be controlled at the molecular level. Molecular orientation of chromophores has been determined by several methods including polarized UV/vis or IR absorption, second harmonic generation (SHG), Electron Spin Resonance (ESR), or resonance Raman scattering. We have measured the incident angle and polarization angle dependencies of polarized UV/vis absorption to study the molecular orientation of alloxazine, porphyrin, and carbazolyl chromophores, or 4,4 -bipyridinium radical cations in LB films[3-12]. Usually in-plane components of transition dipoles of chromophores are... 

In order to measure P by spin-dependent Mott scattering, the incident electron has to be accelerated to 120 keV, scattered on a gold foil, and the backscattered intensities at +120°, called /( left) and /( right), have to be recorded. This gives the signals... 

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