Charge transfer effects in (HfNbTiVZr)C—Shown by ab initio calculations and X‐ray photoelectron spectroscopy

• Published in: Journal of the American Ceramic Society Vol. 107; no. 11; pp. 7562 - 7576
• Main Authors: Osinger, Barbara, Casillas‐Trujillo, Luis, Lindblad, Rebecka, Alling, Björn, Olovsson, Weine, Abrikosov, Igor A., Lewin, Erik
• Format: Journal Article
• Language: English
• Published: Columbus Wiley Subscription Services, Inc 01-11-2024
• Subjects: Carbides; Charge materials; Charge transfer; Chemical bonds; coatings X‐ray photoelectron spectroscopy; Density functional theory; Electronegativity; Electronic structure; high entropy carbide; magnetron sputtering; Photoelectron spectroscopy; Photoelectrons; Solid solutions; Spectrum analysis; Thin films; magnetron sputtering; high entropy carbide; coatings X-ray photoelectron spectroscopy; density functional theory
• ISSN: 0002-7820; 1551-2916; 1551-2916
• DOI: 10.1111/jace.20021

Considering charge transfer effects and the variability of the bonding between elements with different electronegativity opens up a deeper understanding of the electronic structure and as a result many of the properties in high entropy‐related materials. This study investigates the importance of the diverse bonding and chemical environments when discussing multicomponent carbide materials. A combination of ab initio calculations and X‐ray photoelectron spectroscopy (XPS) was used to investigate the electronic structure of multicomponent thin films based on the (HfNbTiVZr)C system. The charge transfer was quantified theoretically using relaxed and nonrelaxed multicomponent as well as binary carbide reference structures, employing a fixed sphere model. High‐resolution XPS spectra from (HfNbTiVZr)C magnetron‐sputtered thin films displayed core‐level binding energy shifts and broadening effects as a result of the complex chemical environment. Charge transfer effects and a changed electronic structure in the multicomponent material, compared with the reference binary carbides, are observed both experimentally and in the density functional theory (DFT) simulations. The observed effects loosely follow electronegativity considerations, leading to a deviation from an ideal solid solution structure assuming nondistinguishable chemically equivalent environments.