On the specific features and transformation of the band structure of mercury-based HTSC compounds
| ISSN: |
1063-7834
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| Source: |
Springer Online Journal Archives 1860-2000
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| Topics: |
Physics
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| Notes: |
Abstract A systematic analysis of the temperature dependences of the thermopower S(T) for different phases of the HgBa2Ca n−1Cu n O2n+2+δ family (n=1, 2, 3) at different doping levels is performed in the framework of a narrow-band phenomenological model. Quantitative estimates of the main parameters of the band responsible for conduction in the normal phase of HgBa2Ca n−1Cu n O2n+2+δ are given for optimally doped samples. The character of the variation in these parameters with an increasing number n of the copper-oxygen layers is discussed. A trend toward broadening of the conduction band with increasing n is revealed, which can be due to the increase of the density-of-states (DOS) peak near the Fermi level with an increasing number of the CuO2 layers responsible for the formation of the conduction band. It is found that an increase in the number n leads to an increase in the fraction of localized carriers in the band owing to a more defective structure observed in the more complex phases of HgBa2Ca n−1Cu n O2n+2+δ. The variations in the band-structure parameters in going from under-to overdoped compositions in the HgBa2Ca n−1Cu n O2n+2+δ family are also discussed.
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| Type of Medium: |
Electronic Resource
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| URL: |