Crystal Growth Facilities

Quartz is a widely occurring mineral, present in many rocks (granite, gneiss, etc.) and sometimes naturally monocrystalline in hydrothermal veins.
By studying and understanding this natural growth environment, scientists have been able to reproduce the same crystallization process in a controlled laboratory setting, leading to the creation of synthetic quartz crystals — a process now known as hydrothermal quartz growth.

At CRYSTALINNOV, we produce our own synthetic α-quartz (SiO₂) using the hydrothermal growth method. The process is performed in a 4-metre-long autoclave, designed to withstand extreme temperature and pressure conditions.

During each growth cycle:
• The autoclave is filled with a solvent, typically NaOH 1M or Na₂CO₃ 0.8M, depending on the equipment and growth conditions.
The chamber is divided into two distinct thermal zones:
• Lower hot zone (T₂): contains the raw material, or lascas (non-monocrystalline quartz fragments with impurities). Under these conditions, the quartz dissolves into the solvent, enriching it with silica.
• Upper cold zone (T₁ < T₂): contains suspended seed crystals — thin natural quartz blades (≈50 mm wide, up to 280 mm long) attached by silver wires.
• Convective circulation continuously moves the silica-rich solution from the hot zone to the cold zone.
• As the temperature drops in the upper zone, silica crystallizes onto the seeds, extending the crystal lattice.
• The depleted solvent then descends back into the hot zone, dissolving more quartz — and the cycle repeats.

In summary:
• Dissolution of lascas in the hot zone
• Upward convection of silica-saturated solvent
• Crystallization onto seeds in the cold zone
• Downward convection of mineral-poor solvent

CRYSTALINNOV advantage: Our 4-metre autoclave and controlled thermal gradients enable the growth of ultra-pure, radiation-resistant quartz, perfectly suited for aerospace, defense, and high-reliability electronics.

The Czochralski process is used to grow LGT (Langatate) crystals from a molten bath. This technique allows precise control over the crystal’s diameter, composition, and structural perfection.

In this process, a seed crystal is carefully immersed into the molten material of the desired composition. The seed is maintained just below the melting point, while the molten bath remains slightly above it — typically around 1500°C for langatate.

As the seed slowly rotates and is pulled upwards, atoms from the melt solidify on the seed’s surface, extending the crystal lattice in a uniform and continuous manner. This process, similar to epitaxy, produces large, defect-free monocrystals with exceptional structural quality.

The growth cycle involves four key stages:
• Descent and contact: The seed is immersed in the molten bath; a slight mass loss occurs as its surface partially melts.
• Cone formation: Slow pulling adjusts the crystal’s diameter to the desired value (max. ≈ 2/3 of the crucible diameter for proper homogenization).
• Ingot pulling: Constant speed, automatically adjusted to maintain stable diameter.
• End of pulling: The speed increases to gradually taper and detach the crystal from the melt.

At the heart of CRYSTALINNOV’s crystal growth capabilities lies a refined Czochralski technique, allowing the production of large, defect-free single crystals.

A high-purity seed crystal is delicately dipped into molten material, then slowly pulled upward while gently rotating. As the crystal rises, atoms from the melt align naturally, forming a flawless and uniform crystal structure.

Thanks to precise control of temperature, pulling speed, and rotation, this process ensures the consistent growth of structurally perfect crystals with excellent purity and optical homogeneity. These materials are ideally suited for high-performance applications in science, technology, and industry — from advanced sensors and optics to piezoelectric and electronic components.

Key Features:
• Controlled growth of large single crystals
• Accurate temperature and pulling rate regulation
• High structural and chemical purity
• Defect-free and homogeneous crystalline structures

CRYSTALINNOV advantage: Combining industrial-grade furnaces with scientific expertise, we deliver reproducible, high-quality single crystals adapted to the most demanding technological applications.