Bulk magnetization

Small metal clusters are also of interest because of their importance in catalysis. Despite the fact that small clusters should consist of mostly surface atoms, measurement of the photon ionization threshold for Hg clusters suggest that a transition from van der Waals to metallic properties occurs in the range of 20-70 atoms per cluster [88] and near-bulk magnetic properties are expected for Ni, Pd, and Pt clusters of only 13 atoms [89] Theoretical calculations on Sin and other semiconductors predict that the stmcture reflects the bulk lattice for 1000 atoms but the bulk electronic wave functions are not obtained [90]. Bartell and co-workers [91] study beams of molecular clusters with electron dirfraction and molecular dynamics simulations and find new phases not observed in the bulk. Bulk models appear to be valid for their clusters of several thousand atoms (see Section IX-3). 

The bulk magnetization is stimulated into processional motion around Bq by a radiofrequency (RF) pulse at Vj, applied tlirough a solenoid-like coil whose axis is perpendicular to Bq. This motion amounts to a nuclear... 

Ferrites can be classified according to crystal stmcture, ie, cubic vs hexagonal, or magnetic behavior, ie, soft vs hard ferrites. A systematic classification as well as some appHcations ate given in Table 1 (see also Magnetic materials, bulk Magnetic materials, thin film). 

Interest is maintained ia these materials because of the combination of mechanical, corrosion, electric, and magnetic properties. However, it is their ferromagnetic properties that lead to the principal appHcation of glassy metals. The soft magnetic properties and remarkably low coercivity offer tremendous opportunities for this appHcation (see Magnetic materials, bulk Magnetic materials, thin film). 

Nuclear Magnetic Resonance. The iateraction of a nucleus with Bq is usually described usiag vector notation and models as ia Figure 2 where the bulk magnetization, Af, and the static field Bq are initially parallel to A radio frequency pulse is appHed ia the xy plane for a duration of t p.s,... 

Fig. 2. Interaction of nucleus (electron) with static magnetic field, Bq, where the bulk magnetization, M, is (a) parallel to Bq and to the -axis, and (b), upon apphcation of a 90° radio frequency pulse along x, M perpendicular to Bq and to the -axis. See text.

See Magnetic materials, bulk Magnetic materials, thin films and particles. 

Figure 1.13 (a) Bulk magnetization vector, M°, at thermal equilibrium, (b) Magnetization vector after the application of a radiofrequency pulse. 

As stated earlier, when placed in a magnetic field, the bulk magnetization of the nuclei will precess about the applied magnetic field with a... 

In this chapter, we have reviewed the family of LnPc2 compounds with an emphasis on its terbium analogue, which covers their synthetic approaches, bulk magnetism, magnetism on different substrates and the fabrication towards different molecular schemes of spintronic devices. 

The same vibration leads to a periodical shift of the surface-state energy levels via the exchange coupling of the surface spin to the bulk magnetization. Bovensiepen and coworkers observed this oscillation of the binding energy, which with the aid of DFT calculations they translated to the interlayer spacing in picometer scale [20,23],... 

This formula shows a smooth decrease of p toward the bulk magnetic moment with increasing N. However, the experimental results graphed in Figure 1 indicate that the variation of p with N has a more complex, oscillatory behavior. Its explanation requires a detailed consideration of the geometry of the cluster and a better treatment of its electronic structure. 

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