{"paper_id":"01eae50e-3f17-4759-bf94-c2de230a37d8","body_text":"Characterization and formation mechanism of black Au films deposited under varied Ar gas pressures | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Characterization and formation mechanism of black Au films deposited under varied Ar gas pressures Kazuto Takada, Midori Kawamura, Takayuki Kiba, Yoshio Abe, Mikito Ueda, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6452364/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 10 Jul, 2025 Read the published version in Discover Materials → Version 1 posted 18 You are reading this latest preprint version Abstract Nanoporous black Au (B-Au) films were fabricated under varied Ar gas pressures (2, 60, and 100 Pa) via thermal evaporation. Film structures and properties were assessed with a consistent Au atom quantity of approximately 1.6 × 10 −2 mol m −2. Irrespective of the deposition pressure, all samples displayed a black appearance devoid of metallic luster, resulting in almost zero specular and diffuse reflections. The highest optical absorption, reaching 99.8%, occurred at 2 Pa deposition pressure. The film density decreased notably with increasing pressure, enabling the creation of films with a density below 1.0 g/cm 3 — equivalent to 5% of the filling factor of bulk Au — by carefully controlling the deposition pressure. FESEM observation and XRD analyses revealed gas-phase metal particle formation in the preparation of B-Au films, similar to our previous study on BAg films. In addition, when deposited on a quartz crystal microbalance (QCM), the B-Au film exhibited enhanced response of the QCM sensor to ethanol vapor. The applicability of this technology to gas sensors has been confirmed. black Au low density formation mechanism QCM gas sensor Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 10 Jul, 2025 Read the published version in Discover Materials → Version 1 posted Editorial decision: Revision requested 05 Jun, 2025 Reviews received at journal 04 Jun, 2025 Reviews received at journal 01 Jun, 2025 Reviews received at journal 27 May, 2025 Reviews received at journal 26 May, 2025 Reviews received at journal 25 May, 2025 Reviewers agreed at journal 19 May, 2025 Reviewers agreed at journal 16 May, 2025 Reviewers agreed at journal 16 May, 2025 Reviewers agreed at journal 15 May, 2025 Reviewers agreed at journal 15 May, 2025 Reviewers agreed at journal 14 May, 2025 Reviewers agreed at journal 07 May, 2025 Reviewers invited by journal 29 Apr, 2025 Editor invited by journal 29 Apr, 2025 Editor assigned by journal 26 Apr, 2025 Submission checks completed at journal 26 Apr, 2025 First submitted to journal 15 Apr, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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