Alumina and hafnia thin films deposited by atomic layer deposition at different temperatures on biomedical stainless steel and titaniumSpajić, Ivan (Avtor) Drev, Sandra (Avtor) Trstenjak, Urška (Avtor) Milošev, Ingrid (Avtor) thin filmsatomic layer depositiontitanium alloysbiomedical steelmedical implantsAlumina and hafnia films produced by the atomic layer deposition were applied to commercially pure Ti and stainless steel 316L specimens for protection under simulated human body conditions. The ALD films were deposited at 180 °C and 260 °C to determine how the deposition temperature affect the films' protective properties. Surface analysis of the ALD films included scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The barrier properties were tested electrochemically using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) techniques in a simulated body solution at 37 °C. Alumina thin films showed substantial barrier properties, but after 30 days of immersion, the alumina dissolved regardless of the deposition temperature. EIS tests themselves promoted the dissolution of alumina. In contrast, the barrier properties of hafnia depended significantly on deposition temperature. Hafnia deposited at 180 °C exhibited substantial protective properties and remarkable stability over an extended immersion period. However, when deposited at 260 °C hafnia films showed strong protection at the outset, but after a few days of immersion, they lost their protective ability due to porosity. The key factors affecting the barrier properties of ALD hafnia films were the proportion of the crystalline phase and how crystallites formed.Elsevier20252025-07-15 09:54:34Neznano22991Nizozemskasl© 2025 The Authors.