Abstract
Exposure to vapors of the metal-phthalocyanines MPc (M = Zn, Ni, Fe or Pb) brings about a systematical variation of optical and superconducting properties of Bi-2212 and 2223 high-Tc oxides. With increasing level of MPc uptake, the spectral weight is gradually transferred from the low to the high-frequency regions, accompanied by a decrease of Tc, diamagnetic response and magnetic hysteresis. Two different types of evolution patterns were observed: the first was characterized by a sharp change at the lowest level of MPc uptake (Tc, hysteresis), while the second featured a gradual evolution (intensities of the electronic absorption bands, diamagnetism). The heavily intercalated Bi-oxides are brightly colored non-conducting materials with well-resolved vibrational features due to both the intercalated MPc molecules and the host oxides. The above evolution patterns are ascribed to a combination of two mechanisms: the decrease of the charge carrier concentration as a result of electron doping into the host oxide, and the increase of anisotropy of the system due to incorporation of insulating MPc molecular layer between the Bi-O bilayers, thereby reducing the coupling along the c-axis. Hence, the intercalation by MPc is shown to be an effective technique for the electron doping leading to a reduction of the charge carrier concentration in the host oxides, in contrast to the intercalation by iodine which leads to a hole doping and to an increase of the number of charge carriers.
| Original language | English |
|---|---|
| Pages (from-to) | 153-163 |
| Number of pages | 11 |
| Journal | Physica C: Superconductivity and its applications |
| Volume | 218 |
| Issue number | 1-2 |
| DOIs | |
| Publication status | Published - 1993 Dec 1 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering
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Evolution of optical absorption and superconductivity in Bi-2212 and 2223 oxides intercalated by metal-phthalocyanines. A systematical study as a function of intercalation level. / Grigoryan, L.; Yakushi, K.; Liu, C. J.; Takano, S.; Wakata, M.; Yamauchi, H.
In: Physica C: Superconductivity and its applications, Vol. 218, No. 1-2, 01.12.1993, p. 153-163.Research output: Contribution to journal › Article
TY - JOUR
T1 - Evolution of optical absorption and superconductivity in Bi-2212 and 2223 oxides intercalated by metal-phthalocyanines. A systematical study as a function of intercalation level
AU - Grigoryan, L.
AU - Yakushi, K.
AU - Liu, C. J.
AU - Takano, S.
AU - Wakata, M.
AU - Yamauchi, H.
PY - 1993/12/1
Y1 - 1993/12/1
N2 - Exposure to vapors of the metal-phthalocyanines MPc (M = Zn, Ni, Fe or Pb) brings about a systematical variation of optical and superconducting properties of Bi-2212 and 2223 high-Tc oxides. With increasing level of MPc uptake, the spectral weight is gradually transferred from the low to the high-frequency regions, accompanied by a decrease of Tc, diamagnetic response and magnetic hysteresis. Two different types of evolution patterns were observed: the first was characterized by a sharp change at the lowest level of MPc uptake (Tc, hysteresis), while the second featured a gradual evolution (intensities of the electronic absorption bands, diamagnetism). The heavily intercalated Bi-oxides are brightly colored non-conducting materials with well-resolved vibrational features due to both the intercalated MPc molecules and the host oxides. The above evolution patterns are ascribed to a combination of two mechanisms: the decrease of the charge carrier concentration as a result of electron doping into the host oxide, and the increase of anisotropy of the system due to incorporation of insulating MPc molecular layer between the Bi-O bilayers, thereby reducing the coupling along the c-axis. Hence, the intercalation by MPc is shown to be an effective technique for the electron doping leading to a reduction of the charge carrier concentration in the host oxides, in contrast to the intercalation by iodine which leads to a hole doping and to an increase of the number of charge carriers.
AB - Exposure to vapors of the metal-phthalocyanines MPc (M = Zn, Ni, Fe or Pb) brings about a systematical variation of optical and superconducting properties of Bi-2212 and 2223 high-Tc oxides. With increasing level of MPc uptake, the spectral weight is gradually transferred from the low to the high-frequency regions, accompanied by a decrease of Tc, diamagnetic response and magnetic hysteresis. Two different types of evolution patterns were observed: the first was characterized by a sharp change at the lowest level of MPc uptake (Tc, hysteresis), while the second featured a gradual evolution (intensities of the electronic absorption bands, diamagnetism). The heavily intercalated Bi-oxides are brightly colored non-conducting materials with well-resolved vibrational features due to both the intercalated MPc molecules and the host oxides. The above evolution patterns are ascribed to a combination of two mechanisms: the decrease of the charge carrier concentration as a result of electron doping into the host oxide, and the increase of anisotropy of the system due to incorporation of insulating MPc molecular layer between the Bi-O bilayers, thereby reducing the coupling along the c-axis. Hence, the intercalation by MPc is shown to be an effective technique for the electron doping leading to a reduction of the charge carrier concentration in the host oxides, in contrast to the intercalation by iodine which leads to a hole doping and to an increase of the number of charge carriers.
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U2 - 10.1016/0921-4534(93)90278-X
DO - 10.1016/0921-4534(93)90278-X
M3 - Article
AN - SCOPUS:0027866380
VL - 218
SP - 153
EP - 163
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - 1-2
ER -