Materials

HPHT growth of centimeter-sized cubic boron nitride crystals

Andrey Katrusha, Weihua Peng, Jianguo Peng, Konstantin Iakoubovskii

Featured August 8, 2026

AI-generated analysis — This is SciGrove's AI interpretation of the paper, not peer-reviewed content. Always refer to the original paper.

Simply

Scientists grew super-hard cBN crystals bigger than a centimeter by cooking them for a long time at very high heat and pressure, using a special metal mix to help them grow.

In depth

The paper presents a significant advancement in synthesizing cubic boron nitride (cBN) single crystals, achieving sizes over 10 mm and improved quality (1.8 cm⁻¹ Raman linewidth). This was accomplished by optimizing the high-pressure high-temperature (HPHT) cell geometry and using a stable Ni-Cr-based solvent-catalyst, enabling prolonged growth durations at high temperatures. The authors also provide a tentative explanation for the observed elongated crystal morphology, attributing it to the relatively low effective diffusivity of boron and nitrogen species in the metallic solvent.

Key Takeaways

1
The study successfully grew cBN single crystals exceeding 10 mm, a substantial increase from the previous maximum of ~3 mm.
2
The synthesized crystals exhibited high quality, demonstrated by a narrow Raman linewidth of 1.8 cm⁻¹, indicating reduced defects.
3
The breakthrough was enabled by optimizing HPHT cell geometry and utilizing a stable, alkali-free Ni-Cr-based solvent-catalyst for extended growth durations.

Conceptual Flow

HIGH LEVEL

Methodology: Growing Bigger, Better Crystals

They used a special hot oven to melt tiny bits of material, then slowly grew them into much bigger, cleaner crystals.

Small Raw Material

Special Metal Mix

High Heat & Pressure

Careful Growing Process

Large, Clean Crystal

Results: Size and Quality Breakthrough

The new way made crystals three times bigger and much smoother inside than before.

Old Crystal Size (Small)

Old Crystal Smoothness (Rough)

New Growing Method

New Crystal Size (Big)

New Crystal Smoothness (Smooth)

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