Microstructure analysis of low electron density contrast metallic multilayers using resonant X-ray reflectivity.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Surface Science

Background:

• Metallic multilayers are crucial in various technological applications.
• Characterizing low electron density contrast multilayers presents significant challenges.
• Conventional X-ray reflectivity (XRR) often lacks sufficient sensitivity for these systems.

Purpose of the Study:

• To demonstrate the enhanced sensitivity of Resonant X-ray reflectivity (RXRR) for microstructural analysis.
• To investigate the microstructural properties (layer thickness, density, interface width) of Cu/Nb multilayers.
• To compare RXRR performance with conventional XRR.

Main Methods:

• Fabrication of Cu/Nb multilayers using magnetron sputtering.
• X-ray reflectivity measurements performed at Cu and Nb K-absorption edges.
• Comparison of reflectivity profiles obtained at resonant and non-resonant energies.

Main Results:

• Pronounced differences in reflectivity profiles were observed between resonant and conventional XRR.
• Enhanced contrast near absorption edges significantly improved data interpretation.
• Accurate determination of layer thicknesses, densities, and interface widths was achieved.

Conclusions:

• Resonant X-ray reflectivity (RXRR) is a powerful technique for characterizing metallic multilayers with low electron density contrast.
• RXRR offers superior sensitivity compared to conventional XRR for such systems.
• This method enables detailed microstructural analysis crucial for material optimization.