This is not a diamond.
Can you believe this crystal contains gallium?
Yes, this is a garnet crystal of gadolinium gallium, commonly called GGG, with the chemical formula Gd3Ga5O12. GGG crystals are typically grown using the Czochralski method, producing large, high-quality single crystals like the one shown below.
Figure 1. The Czochralski method, producing large, high-quality single crystals of gadolinium gallium garnet.
So, what does this attractive object have to do with AI?
How Modern AI Works (and Where the Problems Start)
Modern AI runs on parallel computing, mostly using graphics processing units (GPUs), tensor processing units ( TPUs), and specialized accelerators. The work mainly involves:
- Multiplying huge matrices (large blocks of numbers)
- Moving data constantly between:
- GPU compute cores
- GPU memory
- Other GPUs
- The network (switches, cables, optics)
One major problem that appears as AI scales is “the network,” i.e., data movement becomes a bottleneck. Even if GPUs get faster, the overall system can still slow down. It’s analogous to the fastest chefs forced to wait as narrow hallways slow the flow of ingredients and dishes through a restaurant.
Where GGG Plays a Role
Photonics Stability (Optical “One-way Valves”)
The AI cluster bandwidth/power crunch is forcing a shift from copper to optics, because light can carry much higher data rates with lower loss over distance compared to electricity in copper.
However, optical systems have their own challenges. Tiny reflections can bounce back into lasers, creating noise and instability.
A classic solution is an optical isolator: a component that allows light to pass forward, but blocks it from traveling backwards. Many high-performance isolators rely on magneto-optic garnet films, such as yttrium-iron-garnet (YIG), which rotate light’s polarization in a magnetic field, a phenomenon known as the Faraday Effect. And these high-quality garnet films are often grown on garnet substrates, such as GGG, because the crystal lattice match (YIG lattice constant: ~12.376Å; GGG lattice constant: ~12.383Å) helps produce very low-defect, high-quality films.
Tunable RF/Microwave Components (Cleaning and Steering Fast Signals)
As AI expands into wireless base stations, satellites, radar/sensing systems, and the high-frequency test equipment used to build and validate AI hardware, there is growing demand for components that can select, filter, or tune signals at high frequencies.
YIG-based devices are recognized for their excellent tunability and performance in certain RF/microwave applications. High-quality YIG thin-films are often built on GGG substrates for the same reason: crystal compatibility and material quality. As the “connected AI world” expands, demand for high-performance signal control continues to grow.
Summary
GGG matters in the AI era because it supports the materials stack behind two critical scaling needs:
- More photonics, to move data efficiently.
- Better high-frequency signal control, to keep systems stable, clean, and tunable.
GGG is not the starring actor, but it’s a specialized enabler behind the scenes. As AI, photonics, and high-frequency technologies continue to scale, materials that quietly enable performance and reliability matter more than ever.
Role of Indium Corporation in AI
As mentioned above, GGG is manufactured using the Czochralski method, which uses gallium oxide (Ga2O3) and gadolinium oxide (Gd2O3) as key precursors. We are proud to be the manufacturer of high-purity gallium oxide (Ga2O3), a critical precursor for this process.
Equally important is our commitment to building and maintaining a resilient supply chain. Through strategic sourcing and innovative collaborations, such as partnering with key stakeholders, we are actively working to expand and diversify gallium supply sources.
In partnership with Rio Tinto, Indium Corporation is poised to become a major gallium source for North America and the global market. This collaboration ensures a reliable supply of this strategically vital material. To learn more about Indium Corporation’s gallium-related products, feel free to reach out via our web form!