√2×√2 Structure and charge inhomogeneity at the surface of superconducting BaFe_2-x Co_x As₂ (x=0-0.32 )

• 摘要：

  The structure and electronic property at the cleaved (001) surfaces of the newly discovered pnictide superconductors BaFe_2-x Co_x As₂ with x ranging from 0 to 0.32 are systematically investigated by scanning tunneling microscopy. A √2×√2 surface structure is revealed to dominate for all the compounds and is identified to be Ba layer with half Ba atoms lifted off by combination with theoretical simulation. Charge inhomogeneity is observed at this √2×√2 surface associated with an energy gap of about 30 meV for all the compounds.

• 作者：

  Hui Zhang;Jun Dai;Yujing Zhang;Danru Qu;Huiwen Ji;G. Wu;X. F. Wang;X. H. Chen;Bing Wang;长淦 曾;金龙 杨;建国 侯

• 刊名：

  Physical Review B - Condensed Matter and Materials Physics

• 在线出版时间：

  2010-3-18