X-Ray photoelectron and emission spectra of cubic and rhombohedral tantalum carbonitrides

• Published in: Journal of alloys and compounds Vol. 363; no. 1; pp. 32 - 39
• Main Authors: Khyzhun, O.Yu, Kolyagin, V.A
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2004
• Subjects: Ceramics; Electronic structure; Photoelectron spectroscopy; Tantalum carbides; X-Ray emission spectroscopy; X-Ray emission spectroscopy; Tantalum carbides; Electronic structure; Ceramics; Photoelectron spectroscopy
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/S0925-8388(03)00472-9

X-Ray photoelectron spectroscopy (XPS) and X-ray emission spectroscopy (XES) methods were used to study the electronic structure of rhombohedral Ta 4C 3 and TaC 0.59N 0.15 compounds, as well as of several samples of the cubic TaC x N ∼0.8− x system. The XPS valence band spectra and the XES Ta Lβ 5 bands were derived for the rhombohedral compounds, but the Ta Lβ 5, N Kα and C Kα emission bands for the cubic TaC x N ∼0.8− x carbonitrides were studied and compared on a common energy scale. A strong hybridization of the Ta 5 d-like and C(N) 2 p-like states is characteristic of the compounds of the TaC x N ∼0.8− x system studied, but the hybridization between the C 2 p-like and N 2 p-like states is absent. The substitution of carbon atoms for nitrogen atoms leads to increasing the metallic and ionic components and decreasing the covalent component of the chemical bonding in both systems studied. However, the metallic component is somewhat higher, but the ionic component is smaller to some degree in the rhombohedral compounds compared with those of cubic TaC x N ∼0.8− x system for specimens possessing similar nitrogen-to-carbon ratios.