Spin flip transition

Here we comment on the shape of certain spin-forbidden bands. Though not strictly part of the intensity story being discussed in this chapter, an understanding of so-called spin-flip transitions depends upon a perusal of correlation diagrams as did our discussion of two-electron jumps. A typical example of a spin-flip transition is shown inFig. 4-7. Unless totally obscured by a spin-allowed band, the spectra of octahedral nickel (ii) complexes display a relatively sharp spike around 13,000 cmThe spike corresponds to a spin-forbidden transition and, on comparing band areas, is not of unusual intensity for such a transition. It is so noticeable because it is so narrow - say 100 cm wide. It is broad compared with the 1-2 cm of free-ion line spectra but very narrow compared with the 2000-3000 cm of spin-allowed crystal-field bands. 

Notice how the energies of the Eg and T2g terms from D vary with Dq in very nearly the same way as does that of the ground 2 term. Because of this parallelism, the transition energy from A2g F) Egi D) hardly changes during the course of any vibration that affects the magnitude of Dq. The transition is thus seen as a 

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The most direct, model independent, way to test the validity of the mixing solution is to measure the 3He abundance in the ejecta of low-mass stars, i.e. in planetary nebulae (PNe). The search for 3He in the ejecta of PNe via the 8.667 GHz spin-flip transition of 3He+, painstakingly carried out by Rood and coworkers at the Green Bank radiotelescope since 1992 (see summary of results in Balser et al. 1997), has produced so far one solid detection (NGC 3242, see Rood, Bania, Wilson 1992 confirmed with the Effelsberg radiotelescope by... 

Abstract Spin-orbit coupling is a crucial parameter controlling the spin relaxation rate in solids. Here we review recent theoretical results on the randomness of spin-orbit coupling in two-dimensional structures and show that it exists in a form of random nanodomains. The spin relaxation rate arising due the randomness is analyzed. The random spin-orbit coupling leads to a measurable intensity of electric dipole spin resonance, that is to spin-flip transitions caused by the electric field of an electromagnetic wave. 

An interesting manifestation of the SO coupling is the electric dipole spin resonance, where spin-flip transitions are caused by the electric field of an electromagnetic wave [28]. Let us consider a response of a 2D electron gas in a magnetic held H 2 to a relatively weak external electromagnetic (EM)... 

Microwave Induced Spin-Flip Transition and Detection... 

A microwave cavity placed between SI and S2 can induce spin-flip transitions (F,Mp) = (1,1) —i (1,-1) if tuned to zvhf(H). In order to produce a positive signal, i.e. an increase in counting rate after S2 under resonance condition, S2 will be rotated by 180 degrees with respect to SI. Therefore, the (1, —1) state where Mp = —1 is defined with respect to the magnetic field direction in SI will be a (1,1) state in S2, while the (1,1) state of SI without spin flip would correspond to a (1, —1) state in S2. As a result, if the microwave frequency is off resonance, no H atoms will reach behind S2, while on resonance an increase in the number of atoms should be detected after S2. 

Many transition metal ions are known as luminescent centers as for example Mn2+ in Zn2SiC>4 Mn with a broad emission band due to the electronic transition 4Ti (t eg) — 6A (t g e2). The emitted light is green. On the other hand, the emission band of Mn4+ in Mg4Ge05.5F Mn is narrow with some vibronic interaction structure. The emission in this compound is due to a spin flip transition in t g without any change in chemical bonding. 

Figure 1. The removal of degeneracy in the electron spin state /2> by an applied magnetic field B0 and by coupling with a nuclear spin state (1 = 3 /2). Allowed spin-flip transitions are shown by arrows.

Spin-flip transitions, between the manifolds, are controlled by the incoherent cross section of hydrogen, 80.3 bam, and are enabled by spin exchange with the neutron, / = 1/2. Thus, for the J(l -0) transition... 

A summary of the magnetic phase transitions in the Invar alloy is thus that all transitions occur at much lower volumes than the ferromagnetic ground state volume, except the spin-flip transition, which is predicted to occur somewhere around this equilibrium volume, and which must therefore be taken into account in models for the Invar behaviour. 

Spin-flip transition at a Wigner-Seitz radius of 2.62. 

SAOP functional, all-electron calculation, COSMO spin-flip transitions have been calculated within the Tamm-Dancoff approximation. 

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