Cathodoluminescence microscopy of superconducting and non-superconducting Tl2Ba2CuO6+x polycrystals

C. Diaz-Guerra (1) , J. Piqueras (1) , Christine Opagiste (2)

1 Departamento de Fisica de Materiales
2 LSM - Laboratoire Structure de la Matière

Luminescence properties of Tl2Ba2CuO6+x samples with different superconducting transition temperatures have been studied by cathodoluminescence (CL) in the scanning electron microscope. Independent of the crystal structure, tetragonal or orthorhombic, the CL spectra show two resolved bands at about 430 nm (2.9 eV) and 540 nm (2.3 eV), respectively. The results show that the 2.3 eV emission is related to oxygen content and is more intense in low-oxygen content superconducting samples. It is proposed that this band is related to a complex center involving oxygen vacancies. A comparison of spectra from Tl2Ba2CuO6+x and from precursors used in the synthesis (CuOx, Tl2Ba205) has been carried out.

Mots clés: Superconductivity; thallium compound; Hight Tc superconductors; luminescence properties

Domaines: Supraconductivité [cond-mat.supr-con]

C. Diaz-Guerra, J. Piqueras, Christine Opagiste. Cathodoluminescence microscopy of superconducting and non-superconducting Tl2Ba2CuO6+x polycrystals. Physica C: Superconductivity and its Applications, 1996, 259, pp.121-130. ⟨10.1016/0921-4534(96)00055-X⟩. ⟨hal-00587957⟩