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Most Cited Journal Articles 2002-Materials Science
Following is a CAS database record representing a highly cited journal article.
CAPLUS COPYRIGHT 2003 ACS
Zener (C.A. 45, 6044e) has suggested a type of interaction between the spins of magnetic ions which he named "double exchange." This occurs indirectly by means of spin coupling to mobile electrons which travel from one ion to the next. This interaction is calcd. for a pair of ions with general spin S, with general transfer integral b, and internal exchange integral J. One result is that while the states of large total spin have both the highest and lowest energies, their av. energy is the same as for the states of low total spin. This should be applicable in the high-temp. expansion of the susceptibility, and if it is, indicates that the high-temp. Curie-Weiss const. .theta. should be zero, and 1/.chi. vs. T a curved line. This is surprising in view of the fact that the manganites, in which double exchange has been presumed to be the interaction mechanism, obey a fairly good Curie-Weiss law. The results can be approximated rather well by a simple semiclassical model in which the spins of the ion cores are treated classically. This model is capable of rather easy extension to the problem of the whole crystal, but the resulting math. problem is not easily solved except in special circumstances, such as periodic disturbances (spin waves).
Updated 5/1/2007 8:47:30 AM
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