Experimental magnetic moment

Figure 1 Experimental magnetic moments per atom of Ni, Co and Fe clusters with sizes up to 700 atoms. Reproduced with permission from Ref. 2.

The spin magnetic moments of Ni clusters calculated by Wan et al.48 are in reasonable agreement with density functional calculations,61,63,72 but both approaches, that is, TB and DFT, give values substantially smaller than the experimental magnetic moments. The results of Wan et al. improve by adding... 

Table 8.2. Comparison of SGTE ( ) first-principle and experimental magnetic moments for selected elements (adapted from de Fontaine et al. 1995)...

A number of calculated and experimental magnetic moments for first-row transition metal complexes are given in Table 11.26, showing that the spin-only formula gives results that are in reasonably good agreement. 

The value of J depends on the total orbital angular momentum quantum number, L, and the total spin angulur momentum quantum number, S (Appendix C). Some calculated and experimental magnetic moments for lanthanide complexes are shown in Table 11.25... 

Table 2 Typical experimental magnetic moments of first-row transition metal-ion complexes compared with theoretical predictions...

Atom Electronic configuration of f shell in ion s L J Calculated magnetic moment gVf(j+i) Experimental magnetic moment... 

Atomic number Ion Configuration Ground term Experimental magnetic moment ... 

Table 3.4 Experimental Magnetic Moments for Various Transition Metal Ions...

Table 8. Point charge model crystal field parameters and the calculated and the experimental magnetic moment directions for the rare earth ions in two types of sites in RNi3 compounds (91).

The magnetic moment of Sm3+ (f5) utilising the equation mejj=g J (J +1) 1/2, at room temperature, but it is lower than the actual experimental magnetic moment of 1.54 BM at room temperature reason... 

Table 7.8 Comparisons of predicted and actual experimental magnetic moments (in units of xB) for octahedral transition metal complexes, with from zero to the maximum possible five unpaired electrons.

Table 4.3. Calculated and experimental magnetic moments of transition-metal ions.

A peculiarity occurs for YbNiSb (Skolozdra et al. 1997). This antimonide shows a small nickel deficiency resulting in an exact composition YbNio.gSb. The deficiency has a drastic influence on the properties (see sect. 4.2). The experimental magnetic moments presented by Le Bras et al. (1995a,b) and Skolozdra et al. (1997) differ significantly. Furthermore we should keep in mind that also the lattice parameters for this antimonide differ considerably (see table 11). 

Using the techniques developed in Chapter 10, the purported VB development for [Fe(CN)j] is shown in Figure 16.3. Each of the empty d sp hybrid orbitals on the Fe ion can accept a pair of electrons from one of the sp hybrid orbitals on the CN ligands to form the six Fe-CN coordinate covalent bonds. The experimental magnetic moment of the ferricyanide ion is 2.20 BM, which is in reasonable agreement with the value of 1.73 BM predicted by Equation (15.5). 

One problem with the VB model is that not every Fe + coordination compound has the same magnetic properties. For example, the experimental magnetic moment of [FeFj] (5.85 BM) is more consistent with five unpaired electrons than it is with one electron. The only way to rationalize the magnetic behavior of [FeFj] is to use the VB development shown in Figure 16.4, where the 3d electrons remain unpaired and the much higher lying 4d orbitals are used in the construction of the six cPsp hybrids. Clearly, this is not a very satisfying result. 

SF magnetic spin fluctuation temperature A exp experimental magnetic moment... 

CeCuIn remains paramagnetic down to 4.2 K (Malik et al., 1990a). Curie-Weiss behavior is observed above 40 K with an experimental magnetic moment of 2.50 ns/Ce atom and 0 = 18 K. The temperature dependence of the electrical resistivity shows metallic behavior with a linear part between 100 and 300 K and a curv ature below 100 K. 

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