Temperature-independent paramagnetism and

The second term is temperature-independent paramagnetism and can be verified independently if A, is known from spectral studies. This is an excellent example of the complementary data that may be obtained from magnetic susceptibility and electronic spectroscopic studies. 

Pure manganate(VI) salts exhibit a magnetic moment of 1.75 B.M. at room temperature. The susceptibility follows the Curie law after small corrections for temperature-independent paramagnetism and diamagnetism of the ligands have been applied. 

Step can be a decrease of the Pauli-like contribution of the conduction electrons, but the second one is more probably associated with a reduction of temperature-independent paramagnetism of the inorganic polymeric chains. Just below the second transition a residual value of 1.8 x lO " emu/mol is observed, probably indicative of a temperature-independent paramagnetism, and upon further cooling an increase of the susceptibility due to a Curie tail is observed. This tail shows an increase as with a = 0.6, an exponent that is indicative of disorder [98—100], most probably associated with the solvent. Since this compound is EPR silent no further indications on the origin of the observed susceptibility can be taken from these data alone. 

The two primary causes of shielding by electrons are diamagnetism and temperature-independent paramagnetism (TIP). Diamagnetism arises from the slight unpairing of electron orbits under the influence of the magnetic field. This always occurs so as to oppose the field and was first analysed by Lamb [7]. A simplified version of his fomuila. 

Within the general trend in the behavior across the actinide series, their alloys, and their metallic compounds from superconductors to local moment magnets, the only serious irregularity occurs in some plutonium compounds. These compounds should be magnetic but turn out to be temperature independent paramagnets. 

In contrast to chloride compounds, niobium oxides have a VEC of 14 electrons, due to an overall anti-bonding character of the a2u state, caused by a stronger Nb-O anti-bonding contribution. In some cases, the VEC cannot be determined unambiguously due to the uncertainty in the electron distribution between the clusters and additional niobium atoms present in the majority of the structures. The 14-electron compounds exhibit semiconducting properties and weak temperature-independent paramagnetism. Unlike niobium chlorides, the oxides do not exhibit a correlation between the electronic configuration and intra-cluster bond distances. 

Two other actinyl ions, UO (5/°) and NpO (5/ ), are worth mentioning here. Although the uranyl ion contains no unpaired/electrons, its complexes may display a weak temperature-independent paramagnetism because of... 

Ramsey obtained ay, by first-order and op by second-order perturbation theory (76) variational treatments give similar results (14, 71, 73). The term wp is sometimes called the second-order paramagnetic term and sometimes the high-frequency term (14), because of the dependence of the (temperature-independent) paramagnetism in molecules on the high-frequency matrix elements of the orbital moments (91). 

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