Scientists Capture Gold’s Atomic Makeover Under 10 Million Times Earth’s Atmospheric Pressure

Scientists have finally managed to watch gold—one of the most stable and familiar metals on Earth—transform at pressures so high they rival the conditions deep inside giant planets.

Using cutting-edge laser facilities and ultra-fast X-ray snapshots, a research team from Lawrence Livermore National Laboratory (LLNL) and collaborating institutions recorded gold changing its internal atomic pattern at around 10 million times the pressure of Earth’s atmosphere. This breakthrough not only settles long-standing scientific debates about how gold behaves under extreme compression but also strengthens its reliability as a high-pressure reference material, something crucial across many areas of physics, planetary science, and materials research.

This new work represents the highest-pressure structural measurement ever made for gold, pushing experiments into the terapascal (TPa) regime—territory that only a handful of materials have ever been tested in.

Gold Under Normal Conditions and Why Scientists Care About Its Structure

Under everyday conditions, gold’s atoms arrange themselves into what’s known as a face-centered cubic (fcc) lattice. In this configuration, atoms sit at every corner of a cube and at the center of each cube face. This structure is extremely stable, one reason gold is so resistant to corrosion and makes a reliable reference material for science.

Researchers routinely use gold to calibrate pressure in high-pressure experiments. Since it is easy to detect with X-rays and doesn’t chemically react much, it is considered a dependable standard. But that reliability depends entirely on scientists having an accurate understanding of how gold behaves under the extreme pressures used to study the cores of planets, create new materials, or simulate the environments needed for fusion experiments.

While gold’s behavior under relatively low and moderate pressures is well understood, its behavior at extreme pressures has historically been inconsistent between experiments and theoretical predictions. Some models suggested gold should change its atomic structure earlier than it actually does, while others proposed different structures entirely.

The new experiments finally give a clear picture of what actually happens.

How Scientists Recreated Planet-Like Conditions on Gold

Producing pressures of a million atmospheres is already difficult. Achieving ten million atmospheres requires some of the most advanced tools ever built.

To reach these record-setting pressures, researchers used:

• The National Ignition Facility (NIF) at LLNL
• The OMEGA EP Laser System at the University of Rochester

Both facilities generate precisely shaped, incredibly powerful laser pulses. When these pulses hit a material, they compress it so intensely that its atomic arrangement can change.

But hitting a target with enough force isn’t the real challenge—the problem is measuring what happens inside the material while it is being crushed. At these pressures, transformations occur on billionths-of-a-second timescales. To catch changes in gold’s crystal lattice, researchers used ultra-fast X-ray diffraction, a technique that fires X-rays at the sample and captures how they scatter. The scattering pattern reveals how the atoms are rearranging.

These X-ray snapshots were taken in one-billionth of a second, allowing scientists to see atomic changes as they unfolded.

Another key achievement was keeping the gold in a solid state during compression. At extremely high pressures, materials can heat up so much that they melt instantly. The team created tailor-made laser pulses that allowed them to reach ultra-high pressures without raising the temperature too much, ensuring the gold didn’t liquefy before its structure could be examined.

What Actually Happened to Gold at 1 TPa

The experiments showed that gold’s usual face-centered cubic structure survives to a much higher pressure than many theories predicted. Even when the pressure doubled what exists at Earth’s core, the fcc structure held steady.

But beyond that threshold, something remarkable occurred.

A new atomic arrangement began forming: the body-centered cubic (bcc) structure. In a bcc lattice, atoms sit at the corners of a cube just like in an fcc arrangement, but instead of atoms at the cube faces, there is one atom in the center of the cube.

The surprising thing is that the gold didn’t switch entirely from fcc to bcc. Instead, the two phases coexisted, meaning some regions of the gold adopted the bcc pattern while others kept the fcc pattern. This coexistence had been suggested in earlier theoretical work but was never directly observed under these extreme conditions until now.

This transition marks the first definitive structural confirmation of gold forming a bcc phase in the terapascal pressure range. It also resolves past conflicts between theory and experiment, providing clear data for future models.

Why These Findings Matter Beyond Just Gold

Gold as a High-Pressure Standard

Because gold is used to calibrate pressure in many scientific settings, the results make future high-pressure experiments more accurate. If gold’s structural changes weren’t fully understood, measurements based on it could be off by significant margins. This new research strengthens gold’s role as a reliable standard when studying other materials.

Planetary Science

Pressures of 1 TPa are not common on Earth, but they are common inside giant planets like Jupiter and Saturn. Understanding how materials behave in that regime is essential for modeling:

• Planetary formation
• Magnetic field generation
• Heat transport
• Core composition

Gold itself may not exist inside those planets, but studying its transformation helps refine the physics models used to understand all materials at such pressures.

Fusion and Extreme-Energy Physics

These results are also relevant for scientists working on fusion energy, particularly laser-driven approaches. Fusion experiments create extremely high pressures very quickly, similar to what gold experienced in these tests. Better understanding material responses in such conditions can help guide the design of components and diagnostic tools.

Additional Background: How X-Ray Diffraction Reveals Atomic Structures

X-ray diffraction (XRD) is a foundational technique in materials science. When X-rays hit a material, they scatter off the atoms inside. Because atoms form repeating patterns (crystal lattices), they scatter X-rays in predictable ways.

Each atomic structure produces its own unique diffraction pattern.

In these experiments:

• Gold was rapidly compressed
• Simultaneous X-ray bursts recorded the scattering pattern
• Patterns were compared to known fcc and bcc signatures

The appearance of new scattering peaks revealed the formation of the bcc phase.

Because the entire process occurs within a billionth of a second, these were some of the most challenging diffraction snapshots ever taken. Only facilities like NIF currently have the technology to combine extreme pressures and ultra-fast X-ray imaging in this way.

Additional Background: What Makes the TPa Range So Difficult to Study

Reaching pressures above 500 gigapascals (GPa) has long been a goal of high-pressure physics, but entering the terapascal range introduces extraordinary challenges:

• Materials can melt instantly
• Diamond anvils (used in static compression) begin to fail
• Shock compression heats materials too quickly
• Only ramp-compression laser techniques can maintain solid-state conditions long enough to study structural transitions

This research demonstrates that with the correct laser pulse shaping and X-ray timing, it is possible to reliably probe atomic structure well into the TPa regime.

What Scientists Still Need to Figure Out

Although this work is a major milestone, some questions remain:

• The precise temperature of the gold during compression is not yet perfectly measured, and temperature strongly affects phase boundaries.
• Whether gold might adopt other structures at even higher pressures is unknown.
• The mechanism behind the coexistence of fcc and bcc phases is still being modeled.

Future experiments will aim to refine these details and map out a more complete phase diagram of gold at extreme pressures.

Research Paper

Body-Centered-Cubic Phase Transformation in Gold at TPa Pressures
https://doi.org/10.1103/yzzv-2w81