Reactive Magnetron-Sputtered Tantalum-Copper Nitride Coatings: Structure, Electrical Anisotropy, and Antibacterial...

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Tantalum nitride (TaN) coatings offer hardness and biocompatibility but lack antibacterial properties.
• Incorporating copper (Cu) into TaN can impart antimicrobial action while retaining TaN's benefits.

Purpose of the Study:

• To investigate the impact of varying copper content on the structural, electrical, photocatalytic, and antibacterial properties of TaCuN multilayer films.
• To explore the potential of TaCuN coatings for biomedical applications requiring both conductivity and antimicrobial activity.

Main Methods:

• TaCuN multilayer films were synthesized using reactive magnetron co-sputtering, varying Cu target power.
• Structural and morphological characterization via XRD, STEM/TEM, and EDS.
• Electrical conductivity, optical properties, photocatalytic activity, and antibacterial efficacy against Staphylococcus aureus were evaluated.

Main Results:

• Films exhibited a multilayered structure with alternating Ta-, Cu-, and N-rich phases and a cubic δ-TaN pattern.
• High electrical conductivity anisotropy was observed, with in-plane conductivity significantly exceeding cross-plane conductivity.
• Increased Cu content led to enhanced antibacterial efficiency, achieving 95.6% bacterial growth reduction in the highest-Cu sample.
• Smooth film surfaces minimized bacterial adhesion.

Conclusions:

• Reactive magnetron sputtering allows precise engineering of TaCuN multilayers.
• Optimized TaCuN coatings combine high electrical anisotropy with robust antibacterial functionality.
• These coatings show significant potential for biomedical and protective applications.