Thermoelectric power study on high-Tc Bi-2212 and -2223 oxides intercalated with organic molecules zincphthalocyanine
Journal
Physica C: Superconductivity and its applications
Journal Volume
244
Journal Issue
3-4
Pages
305-310
Date Issued
1995
Author(s)
Abstract
We have systematically studied the behavior of the thermoelectric power S for the high-Tc Bi-2212 and -2223 oxides intercalated with organic molecules zincphthalocyanine (ZnPc). The intercalating level x ranges from zero to 0.02 per formula, while Tc is degraded from 110 to 85 K for (ZnPc) nBi-2223 and from 90 to 61 K for (ZnPc) xBi-2212. It has been observed that the value of S at T = 290 K, S(290), increases with increasing x for both systems. Based on an empirical rule, the carrier concentration n is extracted from S(290). It has been found that n drops sharply for x changing from zero to 0.005, and then decreases gradually with increasing x for both the (ZnPc) xBi-2212 and -2223 systems. The relation of n with x resembles that of Tc with x. Our results suggest that the charge transfer between the ZnPc molecules and the CuO2 layers plays an important role in the Tc-suppression by the ZnPc intercalation. The Tc/Tc0-n relations for these samples fall on the same curve, contrast with the previously reported results. This scaling behavior is consistent with the universality of the Tc/Tc0-n relation which was proposed previously by Zhang and Sato. © 1995.
Type
journal article