Regulating oxygen content and superconductivity in La 3 Ni 2 O 7+ delta
The study systematically varied oxygen content in La3Ni2O7+delta samples to control their structure and superconducting behavior. Controlling oxygen levels dictates whether the material forms a pure bilayer, hybrid-1212, or trilayer intergrowth phase. This stoichiometry directly modulates the upper critical field (Hc2) of the bilayer superconductivity, linking structural defects to superconducting properties.