Magnetic susceptibility molar

Fig. 25. Temperature dependence of the reciprocal magnetic molar susceptibility of MnPS3 (a), Mno.89 PS3 (methyl-tris-octyl- )o.22 (b), Mng 83PS3...

Lithium oxides of Pu, magnetic measurements and reciprocal molar susceptibility vs. 

The dimensionless proportionality factor % is the magnetic susceptibility. The magnetization and consequently also the susceptibility depend on the number of orientable particles in a given volume. A volume-independent, material-specific magnitude is the molar susceptibility xmoi... 

The temperature dependence of the molar susceptibility of a paramagnetic substance follows the Curie-Weiss law (if the magnetic field is not too strong) ... 

Fig. 1 Magnetic moment, eff> per Fe, versus temperature for [Fe( 1,10-phen)(NCShkCA -bpym) (note the relationship fi2eii = 7.997(%T) where % is the molar susceptibility per Fe)...

Another quantitative characteristic of the magnetic manifestation of aromaticity is represented by the exaltation of the total magnetic susceptibility A (68JA811 75MI2). For conjugated compounds, this parameter is given by the difference between Xm and Xm standing, respectively, for the experimentally measured molar susceptibility and the molar susceptibility... 

The magnetic moment, m, is a term used to quantify the magnetic properties of a substance. It is not measured directly, but is obtained from the measured molar susceptibility to which it is related, i. e. 

Table I. Molar Susceptibilities 1 and Magnetic Moments of Complexes...

Fig. 61. Reciprocal magnetic susceptibility vs temperature for CegMSbij, M = Mn, Zn. Inset Molar susceptibility vs temperature for CegMnSbij.

In the light of the magnetic moments of the complex of measurement, we obtained the molar susceptibility and the effective magnetic moment (peff- =2.829 ) of the... 

The molar susceptibility thus has units of volume per mole for all unit systems. In practice, the molar susceptibihty is frequently reported in cgs units as emu Oe mol (Scientists studying magnetism continue to utilize an eccentric mix of mostly cgs units in which the unit of magnetic moment, properly ergOe is given the name of emu . The volume susceptibihty remains dimensionless but is said to have units of emu cm Oe and the molar susceptibihty can be expressed as emuOe mol which is equivalent to cm mol" . See Reference 31 for a lucid discussion of SI units.) ... 

Exchange constants for low-dimensional magnets are most commonly obtained via comparison of experimental data to the predicted behavior of a thermodynamic property for a given model, usually the magnetic susceptibility. Johnston et al. showed that the molar susceptibility xm of the uniform chain can be expressed as a ratio of polynomials in powers ofthe reduced temperature t t = hgT/ 2J ). The coefficients N and D are listed in Table 1. 

An analysis of the magnetization-vs-temperature curve, as shown in Fig. 1, indicates a Neel temperature of approximately 217 K. This value is the highest among those previously reported for difluorides.. Above the Neel temperature, PdFj is paramagnetic and the inverse of the molar susceptibility varies linearly with T (see Fig. 1). For 7 <217 K a ferromagnetic spontaneous magnetization appears, superimposed upon a susceptibility term, linear in the field, which can be represented by the relation... 

The technique of principal component analysis was applied to a set of 12 characteristics associated with aromaticity, including the two above, using a variety of heterocyclic compounds <89JA7>. Three principal components, were found that accounted for most of the variance of the data. Characteristics associated with classical aromaticity, such as the two mentioned above, were dominated by the first component and those associated with magnetic properties, such as the molar susceptibility, were dominated by the second. The In score for oxazole was low, of 16 compounds, only furan was lower. On the other hand, the ii2 score was one of the higher scores. 

When a substance is subjected to magnetic field H, and a magnetization I is induced. The ratio I/H is called the volume susceptibility k and can be measured by a number of techniques, including Gouy balance method, Faraday method and an nmr method. The volume susceptibility is related to the gram susceptibility c and the molar susceptibility cm. 

The magnetic properties were studied in the temperature range of 2-1100 K (Hiebl et al. 1987). The compounds in which the transition-metal component is from the same column of the Periodic Table display a similar behaviour. A temperature-independent exchange-enhanced susceptibility was observed for T = Fe, Ru, and Os. In the case of Co, Rh, and Ir, the molar susceptibility is somewhat lower, but a broad maximum in the temperature dependence of x around 600 K, observed in all three compounds, is reminiscent of spin fluctuators. Antiferromagnetic ordering, indicated for T = Ni, Pd, and Pt by sharp cusps in the x versus T curves, was confirmed by the observation of linear magnetization curves at low temperatures. MCW behaviour is found above the antiferromagnetic transition. 

Thus, to recapitulate, one first makes a direct measurement of the volume susceptibility of a substance from which Xm is calculated, and in accurate work is corrected for diamagnetism and TIP. From this corrected molar susceptibility and the temperature of the measurement, equation 19-12 enables one to calculate the magnetic moment of the ion, atom or molecule responsible for the paramagnetism. 

The magnetic susceptibility of TcFs between 295 and 14 K was found to vary linearly with MT. The molar susceptibility is given by the equation... 

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