Superconductivity in lithium- and sodium-doped mercury-based cuprates

The effect of Na- and Li-doping in Hg-based cuprates has been studied. It has been found that superconductivity can be achieved in samples containing small amount of Na or Li. While little change is found in the crystalline structure, the formed superconducting phase have the onset T-c typically above 140 K and zero-resistance T-c up to 136K. More interestingly, the processing temperature for the doped Hg-1223 can be reduced significantly to near 700 degrees C which is promising for thin films growth on many technologically compatible substrates.