روزنامه با شماره پیاپی سال 2012

4

1870

1873

Reversible magnetization of grain-aligned Ba 2 Ca 3 Cu 4 O 8 + y ( F , O ) 2 (F-0234) with T c ≃ 90.6 K , which is a member with n=4 in the new homologous series Ba 2 Ca n − 1 Cu n O 2 n ( F , O ) 2 was investigated using the Hao–Clem model and fluctuation theories. The almost temperature independence of the Ginzburg–Landau parameter ( κ ) up to 0.9 T / T c and the crossover point in M(T) indicated less 2D character, suggesting no drastic decrease in interlayer coupling compared to other high-Tc cuprate superconductors. The relatively strong interlayer coupling results from the smallest thickness of the charge reservoir block among other multilayered systems. On the other hand, the λ ab ( 0 ) and H c ( 0 ) values derived from the Hao–Clem analysis strongly suggest that the decrease in Tc is due to both the decrease in the carrier density and weakened pairing strength.

Acta Tropica

2012

Acta Tropica