Abstract
Abstract Superconductivity and crystallographic properties of La 2 − x M x CuO 4 − δ (M = Na, K) are studied. In the La 2 − x M x CuO 4 − δ system, superconductivity is detected for x ⩾ 0.2. Oxygen content analysis shows that the system has more oxygen vacancies than the La 2 − x Sr x CuO 4 − δ system. These oxygen vacancies may reduce the hole concentration, and high Na-doping is needed to produce superconductivity. In the La 2 − x K x CuO 4 − δ system, superconductivity is observed for the first time. Resistivity and magnetic susceptibility measurements show that T c (onset) is 40 K and the Meissner volume fraction is about 4% for x = 0.7. The system changes from orthorhombic to a tetragonal K 2 NiF 4 structure at x ≈ 0.3 and only tetragonal samples show superconductivity.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
