Magnetic susceptibility temperature

Table I. Magnetic susceptibility—temperature data for rhodium pentafluoride...

Table 2. Irp4 magnetic susceptibility temperature dependence...

Fig. 1. Magnetic susceptibility—temperature relationships for Cg OsFg andSFg OsFg...

The phase transition temperature shift due to substrate influence can be manifested in the measurements of magnetic susceptibility temperature dependence (Fig. 2.45). It is seen that for EuS-PbS multilayer structure both on KCl(lOO) substrate and without it, the magnetic susceptibility maxima are shifted relatively to each other by 2-3 K, the Tc being lower for free standing film. 

NmI point The temperature at which magnetic susceptibility becomes normal. See anti-ferromagnetism and ferromagnetism. 

Figure A2.3.29 Calculation of the critical temperature and the critical exponent y for the magnetic susceptibility of Ising lattices in different dimensions from high-temperature expansions.

Equation (A2.5.20) is the Curie-Weiss law, and the temperature at which the magnetic susceptibility becomes infinite, is the Curie temperature. Below this temperature the substance shows spontaneous magnetization and is ferromagnetic. Nonnally the Curie temperature lies between 1 and 10 K. However, typical ferromagnetic materials like iron have very much larger values for quantum-mechanical reasons that will not be pursued here. 

Fig. 3. Magnetic susceptibility of plutonium metal as a function of temperature where represent initially high density plutonium and , cast plutonium...

Uranium metal is weaMy paramagnetic, with a magnetic susceptibility of 1.740 X 10 A/g at 20°C, and 1.804 x 10 A/g (A = 10 emu) at 350°C (51). Uranium is a relatively poor electrical conductor. Superconductivity has been observed in a-uranium, with the value of the superconducting temperature, being pressure-dependent. This was shown to be a result of the fact that there are actually three transformations within a-uranium (37,52). 

The ESR spectrum of the pyridazine radical anion, generated by the action of sodium or potassium, has been reported, and oxidation of 6-hydroxypyridazin-3(2//)-one with cerium(IV) sulfate in sulfuric acid results in an intense ESR spectrum (79TL2821). The self-diffusion coefficient and activation energy, the half-wave potential (-2.16 eV) magnetic susceptibility and room temperature fluorescence in-solution (Amax = 23 800cm life time 2.6 X 10 s) are reported. 

In addition, the magnetic characteristics of a material can change as a function of stress (e.g., unannealed series 316 stainless steel can be magnetic after machining), temperature, pressure, and physical and chemical treatment. Therefore, when two paramagnetic materials with similar magnetic susceptibilities are to be separated, the possibility that pretreatment will facilitate subsequent separation should be studied. 

Fig. 10. Temperature dependence of the magnetic susceptibility of various carbon-based materials. The data on HOPG (H//c) are taken at 200 Oe. The data reported for nanolubes, graphite (H in-plane), and diamond, were taken at 4 kOe, those on diamond at 8 kOe. The ordinate axis is negative (after Heremans et al.[26 ).

Fig. 4. Static magnetic susceptibility vs temperature. Nanotubes with the magnetic field perpendicular to the tubes (+), parallel to the tubes (o), unprocessed CNT-containing material (x) and planar graphite (solid line) [31],...

The quadrupole effects mentioned in Section I.B.(l) apparently are small, as magnetic susceptibility measurements18 have revealed that the energy differences between different orientations of an oxygen molecule in a /3-hydroquinone cavity become only noticeable at liquid helium temperatures. 

Magnetic heat capacity of nickel, 133 Magnetic susceptibility, 25 Maleic anhydride, 168 Many electron system, correlations in, 304, 305, 318, 319, 323 Melting temperature and critical temperature for disordering correlation, 129... 

An empirical temperature scale is based on some arbitrary physical property (such as density, electrical resistance, magnetic susceptibility, etc.) that changes in a way that is continuous and single valued. The ITS-90 temperature scale described in Appendix 2 is an empirical scale that is designed to closely approximate the absolute (ideal gas) temperature scale. 

Electrobalances suitable for thermogravimetry are readily adapted for measurements of magnetic susceptibility [333—336] by the Faraday method, with or without variable temperature [337] and data processing facilities [338]. This approach has been particularly valuable in determinations of the changes in oxidation states which occur during the decompositions of iron, cobalt and chromium oxides and hydroxides [339] and during the formation of ferrites [340]. The method requires higher concentrations of ions than those needed in Mossbauer spectroscopy, but the apparatus, techniques and interpretation of observations are often simpler. 

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