Bismuth Valence in a Tl0.7Bi0.3Sr1.6Ba0.4CaCu2Oy Superconductor from X-Ray Photoemission Spectroscopy

作者：Zalecki R; Woch W M; Kowalik M^*; Kolodziejczyk A; Gritzner G

来源：Acta Physica Polonica, A, 2010, 118(2): 393-395.

DOI：10.12693/APhysPolA.118.393

The X-ray electron photoemission spectra of a Tl0.7Bi0.3Sr1.6Ba0.4CaCu2Oy superconductor were measured with Al K-alpha and Mg K-alpha radiation at room temperature. The Bi 4f spectrum was compared to the same spectra of Bi1.75Pb0.35Sr1.9Ca2.05Cu3.05Oy and Tl0.6Pb0.4Sr1.6Ba0.4Ca2Cu3Oy superconductors. In Bi,Pb-based superconductor only one type of Bi3+ ions is present. The Bi 4f spectrum in the Tl,Bi-superconductor consists of two contributions due to the different valences. The component from Bi5+ lines is in higher binding energy than from Bi3+. The ratio of trivalent Bi3+ to pentavalent Bi5+ bismuth ions was calculated from decomposition of the spin-orbit split spectrum of the Bi 4f photoelectrons. The conclusion is that Bi is present in trivalent and in pentavalent form and the ratio of Bi3+ to Bi5+ is 1.87 +/- 0.02.

• 出版日期2010-8