Electron Probe Microanalysis of Ni Silicides Using Ni-L X-Ray Lines

Area of Science:

• Materials Science
• Analytical Chemistry
• Solid State Physics

Background:

• Electron probe microanalysis (EPMA) is crucial for elemental analysis of materials.
• Nickel silicides are important in microelectronics and catalysis.
• Accurate quantitative analysis of nickel silicides using EPMA presents challenges.

Purpose of the Study:

• Investigate anomalies in EPMA of nickel silicides using the Ni L3-M4,5 (Lα) line.
• Identify sources of systematic discrepancies between experimental data and theoretical predictions.
• Improve the accuracy of quantitative analysis for nickel silicides.

Main Methods:

• Performed electron probe microanalysis on various nickel silicide compounds (Ni5Si2, Ni2Si, Ni3Si2, NiSi).
• Measured X-ray emission spectra to obtain self-absorption spectra.
• Determined empirical mass-attenuation coefficients from relative X-ray intensity measurements.

Main Results:

• Examined the dependence of Ni L3-M4,5 k-ratios on mass-attenuation coefficients and partial fluorescence yields.
• Calculated k-ratios using empirical mass attenuation coefficients and modified partial fluorescence yields showed improved agreement with experimental data.
• Satisfactory agreement was also achieved by utilizing the Ni L3-M1 (Lℓ) line instead of the Ni L3-M4,5 line.

Conclusions:

• The accuracy of EPMA for nickel silicides can be enhanced by refining parameters like mass-attenuation coefficients and fluorescence yields.
• The Ni L3-M1 line offers a viable alternative for accurate analysis of nickel silicides, especially when Lα line analysis shows discrepancies.
• These findings contribute to more reliable quantitative analysis in materials science research.