Boosting Signal Intensity in Glow Discharge Optical Emission Spectroscopy via Magnetic Field Confinement.

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Materials Science

Background:

• Glow discharge optical emission spectrometry (GDOES) is a powerful technique for elemental analysis.
• Enhancing signal intensity and sensitivity in GDOES is crucial for analyzing challenging samples and achieving lower detection limits.
• Conventional GDOES systems can be limited in their sensitivity for certain elements and materials.

Purpose of the Study:

• To develop and evaluate a novel magnetic field confinement approach for GDOES.
• To significantly enhance signal intensity and improve detection limits in GDOES analysis.
• To investigate the underlying mechanisms responsible for the observed signal enhancement.

Main Methods:

• Fabrication and testing of 12 different magnetic field confinement configurations.
• Performance evaluation using various elemental and certified reference materials (Al, Ta, In, SiC, AlN, GaN, NIST standards).
• Mechanism elucidation through Stark broadening analysis, COMSOL simulations, and Scanning Electron Microscopy (SEM).

Main Results:

• The C-1-N52 magnetic configuration achieved substantial signal enhancements: 45.3-fold for Al I 396.152 nm and 48.7-fold for Cu I 324.755 nm.
• Significant improvements in sensitivity were observed for multiple elements including Al, Cr, Mn, Mo, Fe, Ti, Ni, Ag, Cu, Co, S, P, and C.
• The detection limit for Cu I 324.755 nm was reduced from 2.24 μg g^-1 to 0.04 μg g^-1.
• Mechanism studies indicated increased electron density (from 3.19 × 10¹⁶ cm^-3 to 3.83 × 10¹⁶ cm^-3) and optimized spatial confinement, boosting collision efficiency.

Conclusions:

• The novel magnetic field confinement strategy effectively enhances GDOES signal intensity and sensitivity.
• The observed improvements are attributed to increased electron density and magnetically optimized spatial confinement, leading to higher plasma collision-excitation efficiency.
• This approach offers a promising method for the sensitive analysis of high-purity advanced materials using GDOES.