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Oxygen K-edge fine structure of TlBa2Ca1-xYxCu2O7 studied by electron energy loss spectroscopy

1989; Elsevier BV; Volume: 159; Issue: 6 Linguagem: Inglês

10.1016/0921-4534(89)90151-2

1873-2143

Daisuke Shindo, K. Hiraga, Satoru Nakajima, Masae Kikuchi, Yasuhiko Syono, Norio Kobayashi, K. Hojou, Takeshi Soga, S. Furuno, H. Otsu,

Superconductivity in MgB2 and Alloys

Abstract The fine structures of the oxygen K-edge in TlBa2Ca1-xYxCu2O7 (x=0, 0.8 and 1.0) with single Tl-O laye rs were investigated by electron energy loss spectroscopy (EELS). The peak corresponding to the hole state near the Fermi energy decreases with the increase of the Y content. Although a small density of the hole state is observable in the compound Tl1Ba2Ca0.2Y0.8Cu2O7, it s hows the semiconducting character. It was pointed out that the decrease of the hole content mainly results in the transition from superconductor to semiconductor in the compound Tl1Ba2Ca1-xYxCu2O7.