Temperature dependence of magnetic moment

A series of 2-imidazoline nitroxides linked to a pyrazole either directly or through a phenylethynylic bridge show the ESR characteristics of the 2-imidazoline nitroxide moiety. An unexpected strong temperature dependence of magnetic moment for solid 109 was discovered that agrees with the Bleaney-Bowers model for isolated... 

Fig. 6. Temperature Dependence of Magnetic Moments for f1 Ci Systems. (Here and in Figs. 7-9,--4f,------5f)...

Table 7. Calculated Temperature Dependence of Magnetic Moment for a 4 f8 System, inCl Symmetry.

Finer details of magnetic properties such as orbital contributions, unusual temperature-dependencies of magnetic moments and magnetic anisotropies can also be calculated by using CFT or, better, ACFT, and the results are generally good approximations. They are not perfect because the basic... 

Fe(C5H4N NH CjHNS CjH4N)2]Br2 -2H20(G). Temperature dependence of magnetic moments [67S45]. 

The esr data of Prins and Reinders 144) were also used by Sohn, Hendrickson, and Gray 146) in a preliminary interpretation of their magnetic susceptibility measurements 99). Thus the g values reported were found to lead to the prediction of a substantial temperature dependence of the moment over the range studied, which was not in fact observed however, the data could be accommodated by assuming either that the distortion parameter, A, increased from about 300 to around 700 cm-1 between 4.2 K and 300 K, or that the 22+(ct 54) state lay only some 350 cm-1 above the ground level. 

Magnetic (Natural) Multipoles. Magnetic dipole. In 1905 Langevin, when aiming at an explanation of Curie s law, i.e. of the temperature dependence of magnetic susceptibility in paramagnetics, attributed a priori and classically a permanent magnetic moment to the microsystems. 

Russian workers have reported some terpyridyl complexes of co-balt(III) 35), and the bis(terpyridyl) cobalt(II) ion is now known. The magnetic properties of Co(terpy) depend critically on the anion present in the crystal thus, at 20°C the magnetic moments are 4.3 (perchlorate), 2.7 (bromide dihydrate), 2.1 (chloride monohydrate), and 2.2 B. M. (aqueous solution). A study of the temperature dependence of the moment for Co(terpy)2Br2 2H20 indicated that no simple explanation was possible 379). The subject has been considered more recently by Judge and Baker 412a). Some peculiar bipyridyl derivatives of cobalt(II) cyanide were reported some years ago 571) these could warrant further investigation. The UV spectra of Co(II) and Co(III) complexes have also been measured. 

Thermomagnetic curves for all samples were measured at 3 kOe. The temperature gradients of the magnetic moment are less than one per cent for all samples. The temperature dependence of magnetization is characterized by the positive curvature. This fact is specifying ferromagnetic ordering of the particles. 

Fig. 21 Crystal structure (a) and temperature dependences of magnetization (b), modulation wavenumber (c), dielectric constant (d), and polarization (e) in TbMnOs crystal [38] (modulations of magnetic moment and lattice displacement are shown at the bottom left)...

The spin-orbit coupling constant plays a considerable role in determining the detailed magnetic properties of many ions in their complexes, for example, the deviations of some actual magnetic moments from spin-only values and inherent temperature-dependence of some moments. All studies to date show that in ordinary complexes the values of A are 70-85% of those for the free ions. It is possible to get excellent agreement between crystal field theory predictions and experimental observations simply by using these smaller A values. 

Figure 7 Field dependence of magnetic moment at various temperatures.

---