ISSN:
1572-9605
Keywords:
Sr(Ca)2CuO3
;
ID-multiband extended Hubbard models
;
spin-Peierls and CDW-BOW
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
,
Physics
Notes:
Abstract Magnetic susceptibility dataϰ(T) of the linear cuprate Sr2CuO3 are discussed. If its CuO3 chains are modeled by spin-1/2 antiferromagnetic Heisenberg chains (AFMHC), we draw attention to a hump in the temperature region of measurements. The slope of the reduced susceptibilityJ χ (T) is considerably smaller than the frequently used Bonner-Fischer predictions, implying an enhanced exchange integralJ ch. We report also exact (pd- model) cluster calculations according to them under reasonable changes in standard CuO2-plane parameter sets; the recently suggested enhanced $$J_{ch^S } \gtrsim 200$$ meVand the experimental charge gapE g≈2 eV cannot be described in a realistic fashion. Assuming classical lattice variables, the consequences of sizable electron-lattice interactions as weak charge density waves (CDW) of spin-Peierls type and specific lattice distortions occurring for open-shell systems are briefly discussed on the basis of total energy minimizations.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00727292
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