ISSN:
1572-9605
Schlagwort(e):
YBa2−x M x Cu3O y (M = K, Na) ceramic cuprates
;
transport property
;
structural stress effect
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Elektrotechnik, Elektronik, Nachrichtentechnik
,
Physik
Notizen:
Abstract The nominal composition of YBa2−x M x Cu3O y (M = K, Na) cuprates with x ≤ 0.30 were synthesized by the standard solid-state reaction technique. X-ray diffraction (XRD) and the resistivity measurements were used to characterize the structure and the superconductivity of the doped cuprates. There was no impurity phase detected within the whole doping range. The structure of the main phase (“123”) has the orthorhombic with P mmm symmetry. With increasing the content of dopants, the lattice constants and some other structural parameters are almost unchanged for M = K, whereas they changed for M = Na. The refined contents of dopants are consistent with that of the nominal ones. The zero resistance temperature T c0 decreases sharply with the increase of the content of potassium in potassium-doped samples as x ≤ 0.20. For sodium-doped YBa2−z Na x Cu3O y cuprates, T c0 varies very little. The difference in superconductivity depression may result from the shift oxygen, which transfers conducting carriers from Cu-O chains to Cu-O2 sheets or the structural stress effect.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1007897506412
Permalink
