Dipole alignment

When this is done, the dependence of k(Ee) upon Ee is even greater than predicted by the dipole-alignment model, and the thermal rate constant predicted from this variation, extrapolated to thermal energies, is more than twice the thermal rate constant found experimentally by using the pulsing technique. 

Dipole-dipole forces, the so-called Keesom forces 8ind8o> appear when both the solvent and solute have dipole moments. Strong interactions are produced as a result of dipole alignment. Dipole interactions are determined by the sum of all the dipoles within a molecule. 

The Curie-Weiss constant, 0, is positive, has the dimensions of temperature, and a value usually close to, but not quite identical to, the Curie temperature, TC- The transition is reversible, and on cooling, ferromagnetism returns when the magnetic dipoles align parallel to one another as the temperature drops through the Curie temperature. 

Figure 2 A dipole-alignment task to be solved by the genetic algorithm.

Just as materials have a response when placed in an electric field, they can have a response when placed in a magnetic field. We will see in this section that many of the concepts of permanent dipoles and dipole alignment in response to an applied field that were described in the context of electrical fields apply to magnetic fields as well. There are a few differences, however, and we will also see that there are fewer materials with specialized magnetic properties than there were with specialized electrical and electronic properties. The magnetic properties of materials are nonetheless important, and they are applied in a number of technologically important areas. 

Antiferromagnets have neighboring magnetic dipoles aligned antiparallel there is no net macroscopic moment in zero applied field and the susceptibility is anisotropic below the Neel temperature, TN (See Fig. 128). 

In the second step the charge arrives at the internal phase passing through the interface. The associated potential is known as the surface potential jump (also called surface potential, surface electrical potential, etc.). It is determined by dipoles aligned at the interface and by surface charges. It is not identical with the Volta potential difference (also sometimes called the surface potential) that has so far been used for the description of the electrical double layer. For the treatment of the electrical double layer, dipoles did not play a role. In particular in water, however, the aligned water molecules contribute substantially to the surface potential jump x- The Galvani potential, Volta potential, and surface potential jump are related by... 

The ion-dipole interaction energy is usually large so that the ion and the dipole align each other. The dissolution of ionic molecules in polar solvents (e.g., water) is due to the ion-dipole interaction (e.g., ZnCl in polyalcohol). When a dipole attracts toward an oppositely charged ion, the comparable ion-ion bond energy in the solid state is released. 

Er The relaxed permittivity, equal to the bulk permittivity when molecular dipoles align with the electric field to the maximum extent possible at the sample temperature. 

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