Anisotropy parallel

IBr2, Aul2 etc.), the structure approximates much more closely to two-dimensional, since the anions are segregated quite clearly into layers, separated by blocks of the organic material. The conductivity anisotropy, parallel and perpendicular to these blocks,is of the order of 500. 

An is the difference in the refractive indices n in the plane of the dra i/ing direction and n perpendicular to iti n = (n, + 2n )/3 is the mean refractive index of the sample and Aa the difference of the polarizabilities of the statistical segment (Aa = optical anisotropy) parallel and perpendicular to the axis of the segment. The quotient of orientational birefringence and stress is defined as the stress optical coefficient C. From the simple model of the network chains the product CT (equation 3) should be independent of T if a slight temperature dependence of n is neglected. CT is proportional to the optical anisotropy of the statistical segment. 

Shearing of the data is perfonned to obtam isotropic spectra in the FI dimension and to facilitate easy extraction of the ID slices for different peaks. Shearing is a projection of points that lie on a line with a slope equal to the anisotropy axis onto a line that is parallel to the F2 axis [24]- Shearing essentially achieves the same as the split-t experiment or delayed acquisition of the echo. Although sheared spectra may look more attractive, they do not add any extra infomiation and they are certainly not necessary for the extraction of QIS and values. 

The anisotropy fiinction r t) = (/ (t) -1+ 21 t)) is detemiined by two polarized fluorescence transients / (t) and/j (t) observed parallel and perpendicular, respectively, to the plane of polarization of the excitation pulse. In tlie upconversion experiment, the two measurements are most conveniently made by rotating the plane of polarization of the excitation pulse with respect to the fixed orientation of the input plane... 

The index of refraction of most polymers is greater parallel to the chain than normal to the molecular axis. Substances showing this anisotropy of refractive index are said to be birefringent. 

If there is a crystal anisotropy, with the easy axis parallel to the shape-anisotropy axis of the particle, the total anisotropy is = shape + crystal and the total switchHig field is = (A — Aj,)Af + 2Aj = crystal anisotropy constant). In the case of practical... 

The first paper about NiFe layers evaporated under an angle was pubHshed in the early 1960s (40). The films prepared this way are often called obHque-incidence or angle-of-incidence films. It was found that these kinds of films show an anisotropy whose strength depends on the angle of incidence of the atoms (a/ during deposition (Fig. 15). If is between 0 and 65 the anisotropy Hes parallel to the film plane and perpendicular to the incidence plane. 

Shape anisotropy is related to the magnetostatic energy of a magnet. A needle-shaped sample tends to line the atomic moments along the needle axis and a disk-shaped sample tends to line these moments parallel to the disk surface. 

The specific resistance of natural graphite crystals is ca Hem (room temperature) along the a axis parallel to the network basal plane. The resistance along the c axis (perpendicular to the basal plane) is ca 1 Q. The cja axis anisotropy ratio is, therefore, ca 10 . Screw dislocations within the crystal may short-circuit the current path parallel to the c axis and cause lower anisotropic ratios separation of planes may cause higher anisotropic ratios. 

In the light of these results, it is not surprising that a very large anisotropy has been calculated [24] to exist in the magnetic susceptibility of nanotubes. The susceptibility with the field parallel to the tube axis is predicted to be as much as 3 orders of magnitude smaller than that with the field perpendicular. Again,... 

Theories of the oxidation of tantalum in the presence of suboxide have been developed by Stringer. By means of single-crystal studies he has been able to show that a rate anisotropy stems from the orientation of the suboxide which is precipitated in the form of thin plates. Their influence on the oxidation rate is least when they lie parallel to the metal interface, since the stresses set up by their oxidation to the pentoxide are most easily accommodated. By contrast, when the plates are at 45° to the surface, complex stresses are established which create characteristic chevron markings and cracks in the oxide. The cracks in this case follow lines of pores generated by oxidation of the plates. This behaviour is also found with niobium, but surprisingly, these pores are not formed when Ta-Nb alloys are oxidised, and the rate anisotropy disappears. However, the rate remains linear it seems that this is another case in which molecular oxygen travels by sub-microscopic routes. 

---