Anti-ferromagnetism

NmI point The temperature at which magnetic susceptibility becomes normal. See anti-ferromagnetism and ferromagnetism. 

Freezing transitions have been examined in recent years by density functional methods [306-313]. Here we review the results [298] of a modification of the Ramakrishnan-Yussouff theory to the model fluid with Hamiltonian (Eq. (25)) a related study of phase transitions in a system of hard discs in two dimensions with Ising internal states which couple anti-ferromagnetically to their neighbors is shown in Ref. 304. First, a combined... 

To understand the properties of this new phase, it is instructive to contrast them with what we know about conventional ferromagnetic and anti-ferromagnetic phases. For example, we recall from elementary statistical physics, that ferromagnetic systems - that is, systems whose couplings Jij = J > 0, for all i, j - have two... 

The limited magnetic measurements of very mixed -metal clusters are summarized in Table XIII. The magnetic behavior of some anti-ferromagnetic very mixed -metal carbonyl clusters (Fig. 82) has been studied by Pasynskii and eo-workers. Temperature dependences of the magnetic susceptibilities of Cr2Co(/t3-S)3(/i-SBu )(CO)2() -C3H4R)2l (R = H. Me) have been determined us-... 

In Science, every concept, question, conclusion, experimental result, method, theory or relationship is always open to reexamination. Molecules do exist Nevertheless, there are serious questions about precise definition. Some of these questions lie at the foundations of modem physics, and some involve states of aggregation or extreme conditions such as intense radiation fields or the region of the continuum. There are some molecular properties that are definable only within limits, for example, the geometrical stmcture of non-rigid molecules, properties consistent with the uncertainty principle, or those limited by the negleet of quantum-field, relativistic or other effects. And there are properties which depend specifically on a state of aggregation, such as superconductivity, ferroelectric (and anti), ferromagnetic (and anti), superfluidity, excitons. polarons, etc. Thus, any molecular definition may need to be extended in a more complex situation. 

Since natural Au consists solely of Au, the interface-selective enrichment technique cannot be applied in Au studies. The absorber thickness for Au is required to be large and therefore multilayered samples of Au layers/3r/ metal layers have to be prepared. The spectra for Au/Fe with varying Au-layer thickness are shown in Fig. 7.83 [437]. The results were interpreted as follows large magnetic hyperfine fields at Au sites exist only within two monolayers at the interface region, which are supposed to be induced by direct coupling with anti-ferromagnetically oriented Fe 3d atoms. 

We also mention the octanuclear chromic wheels [CrF(02CCMe3)2]8 (41) and [Cr8(0H)8(02CPh)i6] (42), which contain eight Cr(III) ions anti-ferromagnetically coupled. 

WCon3(H20)(ConW9034]2]12 have been examined, with ferro- and anti-ferromagnetism found in selected examples. 

Type 3 Cu(II) dicopper centre strong absorption in the near UV (Amax 330 nm) no EPR spectra, the two coppers are anti-ferromagnetically coupled. 

The active site in the aerobic, inactive D. vulgaris enzyme shows no EPR signals. The FTIR spectrum indicates the presence of a bridging CO, in addition to the end-on bound CN/CO pair to each iron atom (Fig. 7.2, trace A). We presently assume that both Fe atoms in the bimetallic site are low-spin ferric and that their S = 1/2 systems are anti-ferromagnetically coupled to a diamagnetic state. 

Anti-Ferromagnetic and Ferri-Magnetic Systems The Effect of Alloying Elements... 

Figure 6.13. Enthalpy vs volume plots for f.c.c., b.c.c. and c.p.h. for (a) Fe and (b) Mn, incoiporating the effect of assuming different magnetic interactions. A ferromagnetic, anti-ferromagnetic, o non magnetic (fiom Asada and Terakuta...

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