Kondo state

In summary, the new data suggest that the features of the pSR spectra of Ybj arise mainly from molecular dynamics (probably within the B12 clusters). This is supported by recent Yb NMR measurements (Ikushima et al. 2000) where a minimimi of l/T was seen around 15 K which ties in with the temperature dependence of ZF-pSR spectral shape. The NMR results on the Yb sites differs from those at the B sites requiring an additional relaxation process for the B ions. There is no compelling evidence that Yb carries a moment. The exact magnetic properties of YhBi2 in its Kondo state remain an open question. 

The tSR data are compatible with either dense spin glass freezing or with the sudden condensation of a coherent Kondo state (for a discussion see, for example, Grewe and Steglich 1991) with slow, but dynamic spin correlations at 2.5K. The latter interpretation ties in with the specific heat data, especially in applied fields. The former could be explained in terms of the magnetic polaron model formulated by Kasuya et al. (1993a,b). 

Summary ZF- tSR sees a rise in relaxation rate below 2.5 K. l vo explanations have been put forward either the formation of a nearly frozen spin state or the sudden condensation into a coherent Kondo state. A fully static limit of spin correlations is not reached. 

The R ions form a periodic lattice, which leads for the 4f electrons together with the conduction electrons to the formation of quasi-particle bands, i.e. the electrons are in a coherent state. Since the magnetic moments either vanish (in the non-magnetic Kondo state) or form themselves a periodic magnetic structure (Kondo systems with magnetic order) there is no elastic scattering of the conduction electrons and therefore Pn,(0) = 0. This is different at high temperatures, where even in a periodic lattice one has disordered moments, which scatter elastically. The coefficient Ai can be calculated analytically. One finds A = j j + with the resistivity in the unitarity limit... 

Nohara et al. (1993) have shown that, as in CePdSn, the Kondo state in CePtSn is caused by the hybridization of the Ce 4f-states with the Sn 5p-states. 

An analysis similar to that discussed in the text yields a set of foiur spin-compensated Kondo states Pa), I f b), l c), and the spin-orbit split state I f s-o) wifi binding energies bE, dEb, dEc and bEs, respectively. These binding energies are given by the expressions... 

Sato et al. (1981) investigated the effects of La substitution on the Kondo state in a Ceo7sLao25B6 alloy (CaB -type no crystallographic details given). 

Sato, N., T. Komatsubara, S. Kunii, T. Suzuki and T. Kasuya, 1981, Effects of La-substitution on the Kondo state in CeBj, in Valence Fluctuations in Solids, eds. L.M. Falicov, W. Hanke and M.B. Maple (North-Holland, Amsterdam) pp. 259-262. 

M. Nishijima, T. Kagohashi, M. lmanishi, Y. Takeda, O. Yamamoto, S. Kondo, Solid State Ionics 1996, 83, 107. 

Gibbs found the solution of the fundamental Equation 9.1 only for the case of moderate surfaces, for which application of the classic capillary laws was not a problem. But, the importance of the world of nanoscale objects was not as pronounced during that period as now. The problem of surface curvature has become very important for the theory of capillary phenomena after Gibbs. R.C. Tolman, F.P. Buff, J.G. Kirkwood, S. Kondo, A.I. Rusanov, RA. Kralchevski, A.W. Neimann, and many other outstanding researchers devoted their work to this field. This problem is directly related to the development of the general theory of condensed state and molecular interactions in the systems of numerous particles. The methods of statistical mechanics, thermodynamics, and other approaches of modem molecular physics were applied [11,22,23],... 

Kondo, J. Urzhumtsev, A. Westhof, E. Two confonnational states in the crystal structure of the Homo sapiens cytoplasmic ribosomal decoding A site. Nucleic Acids Res. 2006, 34, 676-685. 

Formulae similar to (6) have wide application to the movement of a system through an activated intermediate state, and will be applied to a simplified description of the Kondo effect in Chapter 3. For polarons the effect is to allow band motion at low temperatures with well-defined wavenumber k but enhanced effective mass mp given by... 

The ground state of an isotropic antiferromagnet is a singlet, the moments shown in Fig. 3.1 rotating in much the same way as the moment on an impurity rotates in the Kondo problem (see Section 8). The time for rotation, however, is very long, according to Anderson (1952) of order... 

We now ask how these moments can be observed. We have stated that at temperatures below the Kondo temperature there is no true moment but at high temperatures we expect a Curie susceptibility of the form... 

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