Superconducting and Magnetic Behavior in La2-xNaxCuO4

Science  22 Apr 1988:
Vol. 240, Issue 4851, pp. 495-497
DOI: 10.1126/science.240.4851.495


New phases of the type La2-xAxl+CUO4-y have been prepared where Al+ is sodium or potassium. The sodium phases are superconducting for x values from 0.2 to 0.5 at temperatures up to about 40 K. In addition, there are unusual magnetic properties below about 10 K that may be indicative of spin glass behavior. Phases of the type La2-xKxCuO4-y could only be prepared with x values up to about 0.1, and these phases are not superconducting above 4.2 K