Molar magnetization

Curie-Weiss law The molar magnetic susceptibility of a substance may be represented... 

The red line is the ab initio calculated curve. Inset molar magnetization at 2.0 K. (Reproduced from Ref. [72] with permission from The Royal Society of Chemistry.)... 

Figure 8.10 Plots of (a) /MT, (b) /"//M and (c) against temperature T, where X M, /m and /M are in-phase-AC, out-of-phase-AC and DC molar magnetic susceptibilities, respectively, for a powder...

Fig. 15 Temperature dependence of the molar magnetic susceptibility (yM) ofCoII2MnII(PhCOO)6 (TTF—CH=CH—py)2 (white circle) with the best fitted curve full line)...

The temperature dependence of the molar magnetic susceptibility (x) of an assembly of paramagnetic spins without interaction is characterized by the Curie behavior with x = C/T where C = /Vy2( 2.S (.S + l)/3k. It is a very common situation in the organometallic chemistry of radical species when the spin density is essentially localized on the metal atom. Since, in most cases, this atom is surrounded by various innocent ligands, intermolecular interactions are very weak and in most cases are reflected by a small contribution described by a Curie-Weiss behavior, with x = C/(T 0) where 0 is the Curie-Weiss temperature. A positive value for 0 reflects ferromagnetic interactions while a negative value — the most common situation — reflects an antiferromagnetic interaction. 

Fig. 16 The temperature dependence of the inverse molar magnetic susceptibility, a, and the corresponding effective magnetic moment, b, of [Fe(HC(3,5-(CH3)2pz)3)2](BF4)2. Data obtained from [46]...

However, the replacement of two bpym molecules by weaker ligands such as pyridine (py) and particularly NCS affords the compound [Fe(bpym) (py)2(NCS)2]l/4py (Fig. 2). The average Fe-N bond length, 2.186(8) A, at room temperature, is consistent with an iron(II) ion in the HS state. The thermal dependence of XmT (XM=molar magnetic susceptibility, T=tempera-... 

Figure 6.13 Temperature dependence of reciprocal molar magnetic susceptibility of VO. X varies from 0.79 for the curve at the top to 1.32 for the curve at the bottom. X = 1.02 and 0.99 for the curves 5 and 6 from the bottom. (After Banus Reed, 1970.)...

The PVP-Cr(III) complex is paramagnetic because a Cr(IlI) ion possesses three spins (3d3). The molar magnetic susceptibility of the FVP-Cr(IH) complexes given in Table 3 is the same as that of the pyridine-Cr(III) complex. The ESR spectra of PVP-Cr(III) are similar to that of pyridine-Cr(III). Thus, we considered that the Cr(III) complexes on the FVP chain were magnetically dilute and the Cr(III) ions did not interact with each other, although they coordinated along the PVP chain at high concentration. 

JFiq. X-l.—Curves showing the reciprocal of molar magnetic susceptibility of compounds of cobalt(II) as a function of the absolute temperature. 

This chapter is intended to recall the principles of magnetism, the definition of magnetic induction and of magnetic induction in a vacuum which is referred to as magnetic field. Readers may not recollect that the molar magnetic susceptibility is expressed in cubic meters per mol Some properties of electron and nuclear spins are reviewed and finally some basic concepts of the magnetic resonance experiments are refreshed. In summary, this chapter should introduce the readers into the language used by the authors. 

Transition-metal (dn) complexes with open shells belong to the class of paramagnetic materials their magnetic susceptibility is positive (the sample is attracted to the magnetic field) and is temperature dependent. At high enough temperatures and in small fields, the molar magnetic susceptibility normally obeys the Curie law... 

Using the notation ea,i(Bo) for the energy levels, their first derivatives e aj(B0) = (dea>i/dBa)Bo, and second derivatives e",-(Bo) = (32ea>i/dB2a)Ba, the molar magnetization becomes... 

Having determined the van Vleck coefficients, the molar magnetization... 

Derivation perturbation theory for eigenvalues, van Vleck equation Restrictions / gusB - well fulfilled X = /J2S Average molar magnetic susceptibility... 

These individual magnetic moments combine to yield the macroscopic molar magnetization via the Boltzmann distribution scheme ... 

---