Free magnetically induced

This is also known as the free-induction decay (FID). The summed nuclear response detected by the receiver as the magnetization induced by an excitation... 

Table 1 Shape fixity and shape recovery rates for thermally and magnetically-induced SME under stress-free condition for TXF and PDC nanocomposites with ditferent nanoparticle contents for the first cycle. Adapted with permission from ref. [85]. Copyright 2006, National Academy of Sciences, U.S.A. ...

The designs presented are for a laminated composite structure fastened to the vertical rock tunnel wall. This structure is 1.5 m wide radially, 3.7 m long axially, and carries magnetically induced compressive radial forces of 17.3 MN and axial shearing forces of -30.5 MN. These forces are applied via the aluminum bulkhead to the free edge of the strut. The bulkhead is a load-carrying member between the strut and the liquid helium dewar. The strut is... 

This lanthanide Laves phase becomes ferromagnetic at Tc = 61 K under ambient conditions. The saturation hyperfine field and magnetically induced quadrupolar coupling correspond within the experimental errors to the free-ion values (see also fig. 37). Similarly, the isomer shift lies well inside the typieal range of metallic trivalent... 

Flux density is calculated as the permeability of free space times the sum of the magnetic-field intensity and the induced magnetization... 

Figure 4-9. (Ai Precessing moment vectors in field tfo creating steady-state magnetization vector Afo. with//i = 0. (B) Immediately following application of a 90° pulse along the x axis in the rotating frame. (C) Free induction decay of the induced magnetization showing relaxation back to the configuration in A.

Now with Hx turned off, the induced magnetization must relax to its steady-state value. This is the free induction decay phase. Figure 4-9C shows an intermediate stage in the FID is increasing ftom zero toward Mq, and My is decreasing toward zero. As we have seen, relaxes with rate constant l/Ti, and My relaxes with rate constant l/T 2. 

The Maxwell theory of X-ray scattering by stable systems, both solids and liquids, is described in many textbooks. A simple and compact presentation is given in Chapter 15 of Electrodynamics of Continuous Media [20]. The incident electric and magnetic X-ray helds are plane waves Ex(r, f) = Exo exp[i(q r — fixO] H(r, t) = H o exp[/(q r — fixO] with a spatially and temporally constant amplitude. The electric field Ex(r, t) induces a forced oscillation of the electrons in the body. They then act as elementary antennas emitting the scattered X-ray radiation. For many purposes, the electrons may be considered to be free. One then finds that the intensity /x(q) of the X-ray radiation scattered along the wavevector q is... 

Concerning induced orbital moments of U-based intermetallic compounds, many PND experiments have been performed and have shown that the ratio iL/ -is can be used as a measure of the hybridisation [42-44] (in the light actinides, orbital and spin moments are oppositely directed and the neutron magnetic form factors are highly sensitive to the ratio uL/us). Indeed, this ratio is reduced as compared to the free ion expectations (Figure 4). 

At the very beginning of our discussion in 1.1.1, we mentioned that any pulse experiment begins with a delay period. This is necessary so that the spins can return to equilibrium before they are excited. After excitation (when the pulse is turned off) we observe the FID, the free induction decay What decays The induced magnetization of the spins, and this process is known as relaxation. It may be slow or fast, as we shall see, and can also occur via a number of processes, which are discussed in detail in the monographs we have recommended for further reading. We will only treat relaxation very briefly here. 

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