surface-analysis

# Surface Analysis Skill ## Purpose The Surface Analysis skill provides comprehensive capabilities for characterizing material surfaces, enabling detailed analysis of surface composition, chemical bonding states, topography, and interfacial properties critical for understanding surface-sensitive phenomena. ## Capabilities - XPS depth profiling and chemical state analysis - AFM imaging and roughness quantification - Contact angle measurement and surface energy calculation - Profilometry data analysis - Surface contamination identification - Tribological surface analysis - Coating thickness measurement - Adhesion mechanism analysis ## Usage Guidelines ### X-ray Photoelectron Spectroscopy (XPS) 1. **Survey Spectra** - Acquire wide scan (0-1200 eV) for elemental identification - Identify all elements present above detection limit (~0.1 at%) - Note adventitious carbon for charge referencing 2. **High-Resolution Spectra** - Acquire narrow scans for elements of interest - Use appropriate pass energy (20-50 eV typical) - Ensure sufficient signal-to-noise for peak fitting 3. **Peak Fitting** - Apply Shirley or linear background - Constrain FWHM and peak shape within physical limits - Assign chemical states from binding energy shifts 4. **Depth Profiling** - Use Ar+ sputtering for inorganic materials - Consider cluster ions (Ar-cluster, C60) for organics - Monitor for preferential sputtering and mixing ### Atomic Force Microscopy (AFM) 1. **Imaging Mode Selection** - Contact mode: Hard surfaces, atomic resolution - Tapping mode: Soft samples, reduced tip wear - Non-contact: Minimal surface interaction 2. **Image Analysis** - Calculate roughness parameters (Ra, RMS, Rmax) - Identify surface features and defects - Measure step heights and feature dimensions 3. **Force Spectroscopy** - Acquire force-distance curves - Extract adhesion forces - Map mechanical properties (modulus, stiffness) ### Contact Angle Analysis 1. **Measurement Methods** - Sessile drop for static contact angle - Advancing/receding for dynamic behavior - Wilhelmy plate for surface tension 2. **Surface Energy Calculation** - Owens-Wendt method (dispersive + polar) - Van Oss-Chaudhury-Good (acid-base) - Use multiple probe liquids (water, diiodomethane, formamide) 3. **Interpretation** - Hydrophilic: Contact angle < 90 degrees - Hydrophobic: Contact angle > 90 degrees - Superhydrophobic: Contact angle > 150 degrees ## Process Integration - MS-003: Spectroscopic Analysis Suite - MS-015: Thin Film Deposition Protocol ## Input Schema ```json { "sample_id": "string", "technique": "XPS|AFM|contact_angle|profilometry", "analysis_type": "survey|depth_profile|imaging|force_spectroscopy|wettability", "parameters": { "scan_area": "number (um x um for AFM)", "sputter_depth": "number (nm for XPS)", "probe_liquids": ["string (for contact angle)"] } } ``` ## Output Schema ```json { "sample_id": "string", "xps_results": { "elemental_composition": [ { "element": "string", "concentration": "number (at%)", "chemical_states": [ { "state": "string", "binding_energy": "number (eV)", "fraction": "number (percent)" } ] } ], "depth_profile": { "depth": ["number (nm)"], "composition": {} } }, "afm_results": { "roughness": { "Ra": "number (nm)", "RMS": "number (nm)", "Rmax": "number (nm)" }, "features": ["string"] }, "surface_energy": { "total": "number (mJ/m2)", "dispersive": "number (mJ/m2)", "polar": "number (mJ/m2)" } } ``` ## Best Practices 1. Clean samples appropriately before analysis (solvent, plasma) 2. Use charge neutralization for insulating samples in XPS 3. Reference XPS binding energies to C 1s at 284.8 eV 4. Calibrate AFM z-scale with step height standards 5. Use fresh probe liquids for contact angle measurements 6. Report measurement conditions and uncertainties ## Integration Points - Connects with Spectroscopy Analysis for complementary chemical information - Feeds into Thin Film Deposition for process monitoring - Supports Failure Analysis for surface contamination identification - Integrates with Corrosion Assessment for passive layer analysis