Heat-induced transformation of nickel-coated polycrystalline diamond film studied in situ by XPS and NEXAFS

chemistry Medicinal and pharmaceutical chemistry Nano- and molecular-scale electronics Nano-biomaterials and bioscience Nanomagnetics Nanomaterials, thin films and nanointerfaces Nanomedicine Nanometrology and nanomechanics Nano-optics Nanopatterning, self-assembly and nanofabrication Nanostructures for energy and sensing applications Natural products chemistry Organo main group chemistry Other nanotechnology (unclassified) Other organic chemistry (unclassified) Photochemistry and photovoltaics Physical organic chemistry Supramolecular chemistry Controlling the high-temperature graphitization of diamond surface is important for many applications that require the formation of thin conductive electrodes on dielectric substrate. Transition metal catalysts can facilitate the graphitization process. In this work, a polycrystalline diamond films with mixed grain orientation, as well as a synthetic single crystal diamond with a polished (110) face, were covered with a nickel thin film deposited by thermal evaporation method. The effect of nickel on the chemical state of diamond surfaces after high vacuum annealing at a temperature of about 1100 °C has been studied in situ using synchrotron based X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy (NEXAFS). Differences in the morphology and structure of annealed polycrystalline diamond films with and without nickel were evidenced using scanning electron microscopy and Raman spectroscopy. Nickel-coated polycrystalline and single crystal diamond surfaces were found to be more prone to transformation into sp2-hybridized carbon compared to their nickel-free counterparts. XPS data revealed the formation of a thin graphite-like film with low-ordered atomic structure on the surface of the nickel-coated polycrystalline film. The chemical state of sp2-hybridized carbon atoms was found to be insensitive to the face orientation of the diamond micro-sized crystallites; however, the layer defectiveness increased in areas with fine-dispersed crystallites. The angular dependence of NEXAFS spectra at the C K-edge of annealed nickel-coated (110) face of single crystal diamond discovered the vertical orientation of sp2-hybridized carbon layers relative to the diamond surface.

polycrystalline diamond film; single-crystal diamond; graphitization; nickel coating; X-ray photoelectron spectroscopy; near-edge X-ray absorption fine structure spectroscopy | Format: DOCX | Size: 2.3 MB | Download | When a peer-reviewed version of this preprint is available, this information will be updated in the information box above. If no peer-reviewed version is available, please cite this preprint using the following information: Sedelnikova, O.; Fedoseeva, Y.; Gorodetskiy, D.; Palyanov, Y.; Shlyakhova, E.; Maksimovskiy, E.; Makarova, A.; Bulusheva, L.; Okotrub, A. Beilstein Arch. 2025, 202515. doi:10.3762/bxiv.2025.15.v1 Citation data can be downloaded as file using the "Download" button or used for copy/paste from the text window below. Citation data in RIS format can be imported by all major citation management software, including EndNote, ProCite, RefWorks, and Zotero. © 2025 Sedelnikova et al.; licensee Beilstein-Institut. This is an open access work licensed under the terms of the Beilstein-Institut Open Access License Agreement (https://www.beilstein-archives.org/xiv/terms), which is identical to the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0). The reuse of material under this license requires that the author(s), source and license are credited. Third-party material in this work could be subject to other licenses (typically indicated in the credit line), and in this case, users are required to obtain permission from the license holder to reuse the material.