ISSN:
1572-9605
Schlagwort(e):
Low-temperature tetragonal (TLT) phase
;
1/8 problem
;
La2−y−x Th y Ba x CuO4
;
La2−y−x Nd y Ba x CuO4
;
La2−x (Ba, Sr, Ca) x ,CuO4
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Elektrotechnik, Elektronik, Nachrichtentechnik
,
Physik
Notizen:
Abstract In La2−x Ba x CuO4 (LBCO) the transition to a low-temperature tetragonal phase and the suppression of superconductivity occur at the carrier concentration p≈ 1/8 per copper. We will discuss the roles of various material parameters that control this instability. An unusual lattice softening has been found by ultrasonic measurement on La2−x Sr x CuO4 (LSCO). This softening is present only in an in-plane shearing mode and is ascribed to the growth of structural fluctuations in the normal state. These phenomena are closely related because both the structural change in LBCO and the applied strain in LSCO lift the degeneracy of in-plane oxygen sites. They clarify the importance of strong coupling between the normal-state electronic system and the lattice by a Peierls-type mechanism.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00730365
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