Units effective magnetic moment

The unusual solid phase Ca3[CrN3] contains sheets of trigonal planar [CrN3] units with short Cr-N bonds (Cr-N, 186.4, 176.6 pm). The effective magnetic moment of 1.86/tb implies a low-spin configuration, unprecedented for a Cr complex. ... 

Figure 2.56 Effective magnetic moment / eff (in Bohr magneton units) of the liquid-crystalline complex [Tb(LH)3(DOS)3]3 as a function of the temperature. Reprinted with permission from Galyametdinov etal., 2007 [179]. Copyright (2007) American Chemical Society...

The effective magnetic moment, can be obtained from the experimentally measured molar magnetic susceptibility, Xm, and is expressed in Bohr magnetons p ) where l B = eh/Attm = 9.27 x 10 JT . Equation 20.12 gives the relationship between and Xml using SI units for the constants, this expression reduces to equation 20.13 in which Xm is in cm moU. In the laboratory, the continued use of Gaussian units in magnetochemistry means that irrational susceptibility is the measured quantity and equation 20.14 is therefore usually applied. ... 

Most relevant structural features and bond distances (pm), is the effective magnetic moment at room temperature / is die singlet triplet splitting in the dimeric Nij unit. SC = single crystal conductivity and P = compressed pellets conductivity in Q cm at room temperature sem = semiconducting behaviour. 

The magnetisation of a compound, M, is the dipole moment per unit volume. For ferromagnetic compounds, the saturation magnetisation, Ms, when all of the dipoles are aligned, can be measured and used to estimate the effective magnetic moment on the atoms in the stmcture when the unit cell is known. 

The saturation magnetisation of iron is 1.752 X 10 Am Calculate the effective magnetic moment on an iron atom. Iron adopts the A2 stmcture with a unit cell edge of 0.2867 nm. 

Fig. 69. The effective magnetic moment (1. per Gd atom and the Co moment An per formula unit as a function of concentration (Gratz et al., 1980d).

TABLE 15.5 Calculated and experimental effective magnetic moments for the octahedral first-row transition metals in units of Bohr magnetons. 

I. Calculate the predicted spin-only effective magnetic moment for each of the following gas-phase ions in units of Bohr magnetons ... 

Orbital contributions in general determine departures of the g value from the free electron value, and introduce magnetic anisotropy. Equation (1) shows that the quantity XmT is independent of temperature. Sometimes instead of Xm a dimensionless quantity, the so-called effective magnetic moment /iefr=2.828 (xm7) is used, but in the recent literature the XmT value is usually reported. The spin-only XmT and //eff values for various numbers of unpaired electrons are given in Table 1. It is much more common for the magnetic susceptibility to use cgs rather than SI units and we will use the former throughout this chapter. 

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