Spin exchange interaction

The magnitude of the exchange parameters is consistent with a rather high transition point temperature, TN = 30.8 K. The term //3 corresponds to four-spin exchange interactions... 

AH0 EPR line width in the absence of dipolar or spin exchange interaction (initial) 5H dipole-dipole broadening of the EPR line I nuclear spin... 

This single line (go = 1.935 0.005, AH 140 G) is usual for V4+ centers, which are coupled by strong spin-exchange interaction [23, 164], These V4+ ions are localized in some areas with high local concentration (V4+)s (the so called nano-phases - because of their probable size), which can be estimated from the exchange narrowing of a spectrum by the equation [23] ... 

FIGURE 6 Evolution of the intensity of the reflectance structures with in-plane orientation of the electric field (a) [10-10] orientation, (b) [-12-10] orientation [8], Note that the increase of Ais is accompanied by a decrease of Bu and makes it easier to detect A2S. Arrows indicate the average positions of transverse excitonic polaritons The eigenenergies, which are different for the two polarisations due to the spin exchange interaction, can be obtained from a lineshape fitting of the reflectivity spectra. 

EPR spectroscopy provides insight into the structural rearrangement associated with this transformation. The EPR spectrum of the V0HP04-O.5H2O precursor consists of an isotropic line, which is narrowed as a consequence of effective spin-spin exchange interactions within the face-sharing dimers of the struc-... 

Golding s theory of temperature-dependent shifts has been extended to take into account the spin-exchange interaction of the copper atoms. The spin-exchange Hamiltonian is of the type —IJSi.Sj. For the terminal protons H( 1) and H(2) in [6 ] the contact shift can be shown to be given by ... 

The catalytic results described above revealed that the catalytic activity of (NH4)2(V0)3(P207)2-based catalysts is governed by the amorphous vanadium oxide phase. This raises the question on the structure and composition of this component. From the in siiu-ESK measurements under working conditions it can be deduced that the amorphous phase contains ions coupled by effective spin-spin exchange interactions. Catalysts containing this phase (NVPao,NVPi and NVPm) have considerably higher moment quotients than NVP,yB (Fig. 2). 

Vesicles prepared from spin-labeled phospholipids show a broadening of the electron spin resonance (ESR) spectra due to spin—spin exchange interactions (Maeda and Ohnishi, 1974). The exchange of phospholipid molecules between labeled and unlabeled vesicles is accompanied by the disappearance of this spin-spin exchange broadening. 

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