Curie-Weiss behavior

Magnetic measurements of PuFi, between 4.2 and 300 K are consistent at high temperatures with older measurements (10-12). The large temperature dependent diamagnetism observed earlier was not found. Up to 100 K the susceptibility is nearly temperature independent with a value of X ip 2940 x 10-6 emu. The Curie-Weiss behavior near room temperature indicates population of a higher first excited state. The structure of PuFi, is isomorphic with that of UFi, (13), where two different sets of actinide atoms are 8-fold coordinated by a distorted antiprism. 

The magnetic susceptibility of p-[Fe(Cp )2][Pt(mnt)2] follow a Curie-Weiss behavior with 6 - 9.8 K. The dominant ferromagnetic interactions are assigned to the magnetic intrachain D+A interactions from the type I chains, as the contribution from the D+ [ A2]2 D+ unit chains is expected to respect only to the cations due to the strong dimerization of the anions, S - 0 for [A2]2. ... 

For [Fe(Cp )2]2[Cu(mnt)2] the magnetic susceptibility follows a Curie-Weiss behavior, with 6 — 7.95 K [50], The dominant AF interactions observed in this... 

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. 

Little is known about the electrical conductivity of the 550 material. One measurement shows a conductivity of 6 X 10 S/cm at 25 °C for the fully lithiated LiNio 5Mno.502. The magnetic susceptibility exhibits Curie—Weiss behavior at elevated temperatures. ... 

The room temperature magnetic susceptibihty is known for most of the complexes mentioned here, and in general is very near the free ion value. However little low temperature data is available. The dimeric complexes provide an opportunity for magnetic exchange, but preliminary results show Curie-Weiss behavior down to 4 K for the [Yb(C5H4(CH3))2Cl]2 complex 126). 

The static magnetic susceptibility of the synthetic pol uner shows what appears to be Curie-Weiss behavior, with a temperature dependence... 

Figure 5 shows the EPR spectra and intensity for the x=0.06 sample. It is seen that in contrast to the x <0.06 samples at x=0.06 only a single EPR line is observed and the temperature dependence of the signal intensity recovers an usual Curie-Weiss behavior. On the other hand there is still a substantial isotope effect on the EPR line. To understand the change of the EPR spectra at x=0.06, one should first comment on the observability of the phase separation in our EPR experiments. The main difference of the EPR signals from the hole-rich and hole-poor regions is the spin relaxation rate of the Cu... 

On the other hand, the Curie-Weiss behavior is fully suppressed in the LS phase below 48 K. It suggests that the complete C3-symmetry is recovered in the LS molecule and the reorienting dipoles, which are required to guarantee the apparent C3-symmetry in the dynamically disordered HS phase, disappear. A slight growth of s observed between 15 and 40 K arises from a small fraction of thermally excited HS species. Analysis of this part assuming a temperature dependence of the... 

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