Determination of Carbon in Nitrides with C844

Significance of the Topic

Accurate determination of carbon content in nitride materials is essential for quality control in advanced ceramics, electronics, and coatings. Trace levels of carbon can influence mechanical strength, electrical properties, and performance in high-temperature applications, making reliable analysis critical for both research and industrial manufacturing.

Aims and Study Overview

This study presents a robust analytical procedure using the LECO C844 combustion analyzer to quantify carbon in various nitride matrices. Key objectives include establishing sample preparation guidelines, calibration strategies, and performance evaluation to ensure accurate and reproducible results across different nitride materials.

Methodology and Instrumentation

The method employs high-temperature combustion under controlled conditions:

• Instrument: LECO C844 carbon determinator.
• Sample Preparation: Crush solid nitride samples to uniform particle size; remove surface contaminants; load into ceramic crucibles pre-baked at ≥1000 °C.
• Crucibles and Accessories: Preheated 528-018 or 528-018HP crucibles; copper and iron chip accelerators; clean handling tools to prevent contamination.
• Operating Parameters: Furnace mode constant at 100% power; purge time 15 s; analysis delay 20 s; cooling 10 s; integration delay 0 s; integration time 55 s; baseline periods 2 s.
• Calibration: Use steel chip CRM (JK Nr 21) and silicon nitride CRMs (JCRM R007, R008) for linear calibration forced through the origin; perform blank, calibration, and drift corrections prior to sample runs.
• Procedure Steps: 1. Blank determination (three replicates). 2. Calibration/drift correction (three replicates per standard). 3. Sample analysis (three replicates), with accelerators added to each crucible.

Main Results and Discussion

Typical analyses of certified reference nitride materials (Si3N4 R007 @0.136 % C, R008 @0.097 % C) yielded recoveries within 2 % of certified values and standard deviations below 0.002 %. Analyses of aluminum nitride, boron nitride, and zirconium nitride reagents demonstrated consistent repeatability and accuracy, confirming the method’s suitability across diverse nitride matrices.

Benefits and Practical Applications

The described procedure offers:

• High accuracy and precision at low carbon concentrations.
• Minimal sample preparation and rapid throughput.
• Compatibility with routine quality control in ceramic and electronic material production.
• Robust calibration using widely available reference materials.

Future Trends and Potential Applications

Emerging developments may include automation of sample loading and data processing, extension of detection limits to sub-ppm carbon, adaptation to other refractory and composite materials, and integration with complementary analytical techniques (e.g., oxygen or nitrogen determination) for comprehensive elemental profiling.

Conclusion

The LECO C844 combustion method provides a validated, reliable approach for quantifying carbon in nitride materials, combining straightforward sample preparation with rigorous calibration and low detection limits. This protocol supports high-throughput quality control and research applications in advanced ceramic and electronic industries.

Reference

1. LECO Corporation. Determination of Carbon in Nitrides. Application Note, Form No. 203-821-512, 2016.
2. The Ceramic Society of Japan. Certified Reference Materials JCRM R007 and JCRM R008.