Structures, Wettability, and Corrosion Resistance of Annealed Platinum/Ruthenium/Nitrogen Co-Doped Diamond-like Carbon Nano-Composite Thin Film at Different Temperatures
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-01-01 |
| Journal | Journal of Materials and Engineering |
| Authors | |
| Analysis | Full AI Review Included |
Executive Summary
Section titled âExecutive SummaryâThis analysis summarizes the effects of Rapid Thermal Annealing (RTA) temperature (RTAT) on Platinum/Ruthenium/Nitrogen co-doped Diamond-like Carbon Nano-Composite Thin Films (Pt/Ru/N-DLCNC-TF) for protective coating applications, particularly micro-molds.
- Core Material: Pt/Ru/N-DLCNC-TF deposited on Si via DC magnetron sputtering, subsequently annealed (100-400 °C).
- Structural Changes: Increasing RTAT promotes significant graphitization (increased sp2 fraction) and surface segregation of PtRu aggregates.
- Optimal Corrosion Resistance: The film annealed at 200 °C exhibited the best corrosion performance, achieving a polarization resistance (Rp) 15.2 times higher than the as-deposited film, attributed to reduced residual stress and structural defects.
- Surface Property Trend: Higher RTAT (up to 400 °C) increases surface roughness (Ra increases by 21.4%) and hydrophobicity (Water Contact Angle increases by 6%).
- High-Temperature Degradation: Annealing at 400 °C severely decreased corrosion resistance (Rp was 18.2 times lower than the 200 °C sample), due to degraded structural integrity, increased galvanic corrosion risk, and localized film delamination.
- Chemical Composition: Increased RTAT leads to higher surface Pt and Ru content but decreased surface N content, which correlates with reduced surface polarity and increased hydrophobicity.
Technical Specifications
Section titled âTechnical Specificationsâ| Parameter | Value | Unit | Context |
|---|---|---|---|
| Film Type | Pt/Ru/N-DLCNC-TF | N/A | Diamond-like Carbon Nano-Composite |
| Substrate | p-type Si (100) | N/A | Used for deposition |
| Annealing Range (RTAT) | 100 - 400 | °C | Rapid Thermal Annealing (RTA) |
| Annealing Duration | 2 | min | RTA process time |
| Temperature Ramping Rate | 25 | °C/s | RTA process parameter |
| Temperature Cooling Rate | 6 | °C/s | RTA process parameter |
| As-Deposited Ra | 1.4 | nm | Arithmetic average roughness |
| Ra at 400 °C | 1.7 | nm | 21.4% increase due to PtRu segregation |
| As-Deposited WCA | 78 | ° | Water Contact Angle |
| WCA at 400 °C | 82.7 | ° | 6% increase (increased hydrophobicity) |
| As-Deposited ID/IG Ratio | 2.3 | N/A | Raman spectroscopy (indicates aromatic rings) |
| 400 °C ID/IG Ratio | 2.8 | N/A | Confirms increased graphitization |
| Corrosion Electrolyte | 0.5 M HCl | N/A | Solution used for polarization tests |
| Corrosion Resistance (200 °C) | 15.2x Higher Rp | N/A | Compared to as-deposited film |
| Corrosion Resistance (400 °C) | 18.2x Lower Rp | N/A | Compared to 200 °C annealed film |
| As-Deposited C 1s FWHM | 1.88 | eV | Full-width-at-half-maximum |
| 400 °C C 1s FWHM | 1.65 | eV | Decrease indicates reduced bond angle disorder |
Key Methodologies
Section titled âKey MethodologiesâThe Pt/Ru/N-DLCNC-TF was prepared using DC magnetron sputtering followed by Rapid Thermal Annealing (RTA).
1. Film Deposition (DC Magnetron Sputtering)
Section titled â1. Film Deposition (DC Magnetron Sputtering)â- Targets: Graphite (99.999% C) and Pt50Ru50 (99.99%).
- Power Density:
- Graphite Target: 52 W/in2.
- Pt50Ru50 Target: 2.5 W/in2.
- Gases and Flow Rates:
- Working Gas: Argon (Ar) at 50 sccm.
- Reactive Gas: Nitrogen (N2) at 1 sccm.
- Deposition Environment:
- Background Pressure: 7.5 x 10-6 Torr.
- Deposition Pressure: 3 x 10-3 Torr.
- Substrate Conditions: Substrate bias of -30 V, rotated at 22 rpm.
- Duration: 120 minutes.
2. Post-Treatment (Rapid Thermal Annealing - RTA)
Section titled â2. Post-Treatment (Rapid Thermal Annealing - RTA)â- Equipment: Jipelec Jetfirst 100 RT processor.
- Temperature Range: 100 °C, 200 °C, 300 °C, and 400 °C (RTATs).
- Duration: 2 minutes at peak temperature.
- Atmosphere: Nitrogen environment supplied at 2000 sccm.
3. Characterization Techniques
Section titled â3. Characterization Techniquesâ- Chemical Composition/Bonding: X-ray Photoelectron Spectroscopy (XPS, Kratos Axis Ultra).
- Amorphous Structure: Renishaw S2000 micro-Raman spectroscopy (He-Ne laser, 632.8 nm).
- Surface Topography/Roughness: Digital Instruments S-3000 Atomic-Force-Microscopy (AFM) in tapping mode (1 ”m x 1 ”m scan size).
- Wettability: FTA200 system using distilled water droplets (Water Contact Angle).
- Corrosion Resistance: EG & G 263A potentiostat/galvanostat workstation in 0.5 M HCl solution (Tafel slopes, Polarization Resistance Rp).
Commercial Applications
Section titled âCommercial ApplicationsâThe development of highly durable, low-adhesion, and wear-resistant coatings is critical for extending the service life of precision tools. This Pt/Ru/N-DLCNC-TF technology is directly applicable to:
- Micro-Molding and Micro-Fluidics: The primary application cited. DLC coatings are essential for reducing adhesion and friction in miniature micro-molds (e.g., Si and steel molds) used for fabricating micro-fluidic devices, which typically suffer from short service life due to high adhesion and wear.
- Protective Coatings: General use as a protective coating for steel components susceptible to corrosion, especially in environments containing moisture or chlorides (e.g., industrial equipment, marine applications).
- High-Wear Components: Due to the high hardness and excellent wear resistance inherent to DLC films, these nano-composite coatings can be used on moving parts requiring low friction and high durability.
- Catalysis and Electrochemistry: The incorporation and surface segregation of Pt and Ru aggregates suggest potential applications in electrocatalytic systems, where the metal content and structure are crucial for reaction efficiency.