Surface structures of (Hg, T1)-based oxides studied by high-resolution electron microscopy

Surface structures of the (Hg,T1)-based superconducting and related oxides were studied by high-resolution electron microscopy. The {100} planes of the 1201-type structure were found to be stable, and Hg0.5Tl0.5Ba2CuO5 showed a preferred atomic surface consisting of Ba layers. The {001} planes were also stable in HgTlBa2CuOx and TlBa2CaCu2O7. The present work indicates that the stable {100} planes of (Hg,Tl)-based superconducting oxides would be suitable for future device applications.