Magnetic field-regulated glow discharge sputtering for enhanced depth-profiling and antibacterial analysis of Ag-doped TiN coating.

A novel satellite-like magnetic field-regulated (SLM) configuration is developed to enhance the depth-profiling and antibacterial analysis of Ag-doped TiN coating on Al substrate (Ag:TiN/Al) using glow discharge mass spectrometry (GDMS). COMSOL simulations reveal that the SLM configuration produces a unique magnetic field distribution through an antiparallel pole arrangement with six-fold symmetry. This creates a distinctive central circular magnetic field, which effectively controls electron motion, enhances central sputtering, and minimizes the edge effect, thereby improving depth-profiling performance. Applied into GDMS analysis of Ag:TiN/Al, SLM configuration achieves an exceptional depth resolution of 0.39 μm and a sputtering rate of 0.23 μm/min, outperforming the non-magnetic condition. It produces a flatter crater profile and increases GDMS signal intensities for Al, Ti, and Ag by 2.3, 1.8, and 2.0 times, respectively. Fuzzy synthetic evaluation method (FSEM) results confirm that SLM configuration with 60.0 mT significantly enhances GDMS depth-profiling analysis performance, especially under optimal discharge pressure of 6.50 mPa. SLM configuration further enables precise quantification of the correlation between Ag concentrations at different depths of Ag:TiN/Al and its antibacterial properties. This innovative method offers a sensitive approach for analyzing elemental distributions in coatings, offering valuable insights to guide the design and optimization of antibacterial coatings.