| Autor: |
Kodai Kaneyasu, Ryosuke Sakagami, Masanori Matoba, Yoichi Kamihara |
| Zdroj: |
Japanese Journal of Applied Physics; 3/1/2019, Vol. 58 Issue 3, p1-1, 1p |
| Abstrakt: |
Polycrystalline Ca and F co-doped LaFeAsO samples (La1−xCaxFeAsO1−yFy) were synthesized by solid-state reactions. Samples with nominal composition: (y − x) ≤ 0.05 did not show superconductivity at temperatures T > 4.2 K, although an anomalous kink of the ρ–T curves, which is related to crystallographic phase transitions, was observed at T ∼ 150 K. Samples with nominal composition: (y − x) ≥ 0.15 did exhibit superconductivity. The superconducting transition temperature (Tc) of co-doped LaFeAsO with nominal composition: (x, y) = (0.25, 0.50) was determined to be Tc = 31.5 K, which is higher than the highest Tc value observed for LaFeAsO1−xFx materials synthesized under ambient pressure. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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