ISSN:
1572-9605
Schlagwort(e):
heavy fermions
;
spinodal segregation
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Elektrotechnik, Elektronik, Nachrichtentechnik
,
Physik
Notizen:
Abstract Two equilibrium bond lengths coexist in the (001) CuO2 planes of the copper-oxide superconductors; (Cu–O)loc 〉 (Cu–O)itin correspond, respectively, to the antiferromagnetic parent and overdoped phases. In the range 0 〈 p ≤ 0.1 holes/Cu atom of these planes, each hole occupies an itinerant-electron cluster of 5 to 6 Cu atoms in a (CuO)loc matrix at temperatures T 〉 T*; below T*, a spinodal phase segregation between parent and vibronic phases occurs. Evidence is cited for a condensation in the vibronic phase on lowering the temperature to one hole per 3 Cu atoms in alternate Cu–O–Cu rows. Ordering of the holes at a $$p_c \simeq \tfrac{1}{6}$$ leads to the formation of itinerant vibronic states, and BCS coupling of the heavy fermions below T c gives a superconductive condensate of symmetry $${\text{d}}_{x^2 - y^2 } $$ .
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1007890920990
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