The delicate internal structure of platinum crystals growing in liquid metal has been revealed, according to new research employing a powerful X-ray technique that reveals new implications for quantum computing.
UNSW Professor Kourosh Kalantar-Zadeh, with the University of New South Wales (UNSW), led the study, which was reported in a recent paper in Nature Communications. The team behind the project has a history of specializing in exploiting liquid metals to produce new materials and green catalysts that improve industrial chemical reactions.
Dissolving Metal
Liquid metals present a curious contradiction, combining properties that normally remain separate. These unusual characteristics could unlock future manufacturing techniques for advanced materials, with potential applications ranging from new methods for extracting hydrogen from water to emerging uses in quantum computing.
“Liquid metals are also very good solvents, with a powerful ability to dissolve other metallic elements, like sugar in water,” said Professor Kalantah-Zader.
Just as hot water dissolves more sugar before crystals form as the solution cools, liquid metals behave in a similar way: when saturated, they form crystals of excess metallic elements as temperatures drop.
Making Liquid Metal Crystals
The researchers chose Gallium as their liquid metal medium, a material whose properties alter significantly at relatively low temperatures. Left at room temperature, it is a solid block of shimmer metal, yet when increased to just 85.58°F, it transforms into a puddle of liquid metal.
In some experiments, the team used pure gallium, while in others they heated a gallium-indium alloy to 500°C to maximize solubility before dissolving platinum beads into the molten mix. As the liquid metal cooled, platinum crystals began to grow.
“Witnessing the formation of crystals inside liquid metals like Gallium is a challenging task,” Kalantah-Zader said. “Gallium is a very dense element whose atoms are tightly packed and is so opaque it is impossible for most microscopes to pass through a thick layer of Gallium. It was a really special moment to be able to develop a method to do this.”
X-Ray Observations
To peer into the opaque metal, the team turned to X-ray computed tomography, a common medical imaging technique that provided 3D views of the crystal interiors. Over minutes and hours, they watched platinum crystals develop within the gallium medium, forming rods and snowflake-like structures.
“To see how liquid metals can be harnessed to shape the future of smart materials and identify those that play important roles in energy sources, we need to understand their metallic and chemical properties, inside and out,” said Professor Kalantah-Zader.
“With X-ray computed tomography, we can now truly see what we are working with and design liquid metal grown crystals to grow more precisely,” he added.
Working with Liquid Metal Crystal X-Rays
The X-ray computed tomography provided the team with cross sections of the action, which they had to collate into full 3D images. From those completed images, they were able to fully map the crystal formation process as Gallium and platinum cooled.
“We observed with fascination how metallic particles of various crystal orientations grew inside liquid metals by changing the temperature and environmental conditions,” said co-author PhD student Ms Moonika Widjajana.
“This study illustrated how X-ray computed tomography can overcome the challenge of observing crystal growth within liquid metal – an opaque material that is usually impossible to penetrate with light and electrons,” Widjajana added.
Although current imaging technology provides only low-resolution views, more advanced high-resolution tomography systems are on the horizon. Such improvements, the team says, will further expand their understanding of how these crystals form.
The paper, “Observing Growth of Metallic Crystals inside Liquid Metal Solvents,” appeared in Nature Communications on November 24, 2025.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.