Abstract
The paper reports on coupled DC electrical conductivity measurements and oxygen non-stoichiometry determinations on SmBa2Cu3O6+x at high temperatures (300-750°C) under oxygen partial pressures from 10-1 to 10-5 atm. Under the lowest oxygen pressures (10-4 and 10-5 atm) and at the highest investigated temperatures (T > 700°C, for the former pressure) the material shows semiconducting behavior. In the other [T, P(O2)] field the material shows metallic conductivity. The amount of (positive) carriers is controlled by equilibrium with external oxygen coupled to oxygen point defects. A change in the mechanism of hole injection is well apparent at the transition between the tetragonal and the orthorhombic phases. Indications are given about the large polaron nature of the holes at high oxygen content.
Original language | English |
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Pages (from-to) | 257-263 |
Number of pages | 7 |
Journal | Physica C: Superconductivity and its Applications |
Volume | 308 |
Issue number | 3-4 |
DOIs | |
State | Published - 20 Nov 1998 |
Keywords
- 123 superconductors
- Large polarons
- SmBaCuO