X-ray photoelectron spectroscopic studies of glasses in the MoO3-Bi2O3 and MoO3-Bi2O3-CuO systems

• Published in: Journal of non-crystalline solids 2014-10, Vol.401, p.175-180
• Main Authors: Milanova, M., Iordanova, R., Kostov, K.L., Dimitriev, Y.
• Format: Article
• Language: English
• Subjects: Absorption spectra; Amorphous structure; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Disordered solids; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Formations; Glass; Glass structure; Glass transitions; Glasses; Networks; Non-traditional glasses; Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Physics; Reflectance; Specific phase transitions; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; X-ray photoelectron spectroscopy; X-rays; XPS
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2014.01.032

The local structure and the connectivity in the amorphous network of glasses from MoO3-Bi2O3 and MoO3-Bi2O3-CuO systems have been studied by comparative analysis of crystalline and amorphous phases using X-ray photoelectron spectroscopy. According to the XPS data the amorphous networks of both glass systems consist mainly of MoO4 tetrahedra as well as of small amounts of MoO6 octahedra. Based on the O1s spectra analysis it was suggested that the MoO6 octahedra are connected by bridging MoOMo bonds, while the MoO4 tetrahedra participate in the formation of mixed type BiOMo bonds. The presence of mixed BiOMo bonds with a relatively significant covalent character is crucial for the glass formation. Mainly Mo6+ and Bi3+ ions were detected in MoO3-Bi2O3 glasses and additionally Cu+ and Cu2+ ions were observed in MoO3-Bi2O3-CuO amorphous samples. UV-visible diffuse reflectance analysis confirmed the XPS data, revealing the presence of Mo6+, Bi3+ and Cu2+ ions in the glasses. Formation of MoO4 tetrahedral units (absorption band at 260nm) in the amorphous network was also found by optical absorption spectra. The role of MoO3 as glass former was confirmed. •XPS comparative study of amorphous and crystalline phases in the MoO3-Bi2O3 system.•XPS analysis revealed MoO4 and MoO6 as main structural units of the amorphous network.•Formation of mixed BiOMo bonds is crucial for the glass formation.•Mainly Mo6+ and Bi3+ ions are detected in MoO3-Bi2O3 glasses.•Mo6+, Bi3+, Cu+ and Cu2+ ions are established in MoO3-Bi2O3-CuO amorphous samples.