Furnace crystallization benefits greatly from being conducted in space due to the microgravity environment, which minimizes the effects of convection and buoyancy that are problematic on Earth. When materials crystallize on Earth, gravity induces convective currents within the melt, which can cause uneven distribution of impurities and dopants, leading to structural defects such as cracks, bubbles, and compositional inhomogeneities. These imperfections reduce the performance of the resulting crystals, especially in applications requiring high-purity materials, such as semiconductors and scintillators.

In the near-zero gravity conditions of space, such as on the International Space Station (ISS), these convective forces are almost eliminated, allowing for diffusion-controlled growth. This results in a more uniform distribution of elements within the crystal, reducing defects and improving the material’s quality. For example, semiconductor crystals grown in space have demonstrated superior purity and fewer structural imperfections, enhancing their efficiency in radiation detection and electronics​.

Microgravity furnaces, like the Solidification Using a Baffle in Sealed Ampoules (SUBSA) on the ISS, enable researchers to carefully control the crystallization process by minimizing these unwanted effects, allowing for better observation and analysis. The furnace can achieve precise temperature control, essential for solidifying materials with minimal disruptions. This has proven beneficial in experiments involving materials such as indium iodide and indium antimonide, which are key for applications in radiation detection.

Quantitatively, crystals grown in space have shown reductions in defect rates by several orders of magnitude compared to those grown on Earth, making the process commercially attractive for industries reliant on high-performance materials, such as semiconductor manufacturing​