Laser-heated diamond anvil cell studies and intermetallic formation under pressure: Sn and Pb–Sn as examples

High-pressure and high-temperature experiments provide a unique opportunity to explore the phase stability, melting behavior, and chemical interactions of materials under extreme conditions. Diamond anvil cells (DACs), combined with laser heating, enable access to pressures approaching 200 GPa and temperatures reaching 6000 K [1]. When coupled with in situ X-ray diffraction, these techniques offer direct insight into crystallographic structures, phase transitions, and the evolution of phase stability under compression and heating. Beyond the study of individual elements, the addition of pressure and temperature as external parameters opens new possibilities for exploring chemical reactions and the formation of intermetallic compounds.

The first part of this seminar will focus on the experimental setup and methodology for high-pressure, high-temperature measurements, with particular emphasis on determining the melting curve of Sn [2]. The experimental strategies used to generate and control high temperatures in a DAC will be presented, alongside the main challenges associated with laser-heated experiments, including the identification of melting, potential chemical reactions, and the reliability of temperature measurements. Tin is a particularly interesting benchmark for such investigations, notably because of its high reflectivity, which makes laser heating and temperature determination especially challenging.

Beyond its melting behavior, Sn also offers an intriguing platform for investigating pressure-induced intermetallic formation. Its rich high-pressure phase diagram, characterized by successive structural transformations (𝛽−Sn, bct 𝛾−Sn, bcc−Sn, hcp−Sn), raises the possibility that compression may promote new chemical interactions and stabilize previously unexplored intermetallic phases. This prospect is supported by reports of pressure-induced phase formation in Sn-containing systems, including Sn–In and Sn–Hg [3], but also in simple eutectic system with no mixture under room pressure such as Fe-Mg [4]. The second part of the seminar will then present preliminary high-pressure results on an eutectic Pb–Sn alloys, focusing on structural transformations and the possible stabilization of pressure-induced phases. This system is particularly interesting because of its simple eutectic phase diagram and the absence of stable intermetallic compounds at ambient pressure. This system therefore provides an interesting model for investigating whether compression can modify phase stability and favorize the formation of new phases that are not observed under ambient conditions.

References:

[1] Anzellini, S., & Boccato, S. (2020). A practical review of the laser-heated diamond anvil cell for university laboratories and synchrotron applications. Crystals, 10(6), 459-1.

[2] Fréville, R., Dewaele, A., Guignot, N., Faure, P., Henry, L., Garbarino, G., & Mezouar, M. (2024). High-pressure–high-temperature phase diagram of tin. Physical Review B, 109(10), 104116.

[3] Degtyareva, O., Degtyareva, V. F., Porsch, F., & Holzapfel, W. B. (2002). Phase transitions under high pressure in binary Sn alloys (with In, Hg and Ga). Journal of Physics: Condensed Matter, 14(3), 389-406.

[4] Desseaux, M., Andrieux, J., Dezellus, O., Morard, G., Parisiades, P., Crivello, J. C., & Billard, A. (2026). Fe 2 Mg 3 stabilization and solid-solution preliminary observations in the Fe-Mg system at high pressure and high temperature. Physical Review B, 113(9), 094114.

Robin FRÉVILLE graduated from ISAE-ENSMA in 2020 with an engineering degree in materials science. He then pursued a PhD at CEA (Arpagon, France) in physics, focusing on “Phase Transitions and Associated Microstructures in Metals under Extreme Conditions.” After completing his PhD in 2023, he joined the Institute for Applied Materials at the Karlsruhe Institute of Technology (KIT), Germany, for a two-year postdoctoral fellowship. His research investigated “Interactions between Dislocations and Grain Boundaries in Copper during Fatigue Testing.” In 2025, he joined the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, for a second postdoctoral fellowship. At beamline ID15B, he contributes to beamline operations, commissioning activities, and associated research programs, with a focus on high-pressure crystallography of metals and binary alloys.

Expertise

• X-ray diffraction and crystallography under extreme conditions (pressure, temperature)

• Development of high temperature measurement using induction heated DAC

• High pressure techniques: Diamond Anvil Cells (DAC), laser-heating, Paris-Edinburgh press.

• Sample preparation and analysis (SEM-EBSD, FIB-milling, fs-laser)

• 3D X-ray Laue microdiffraction using synchrotron radiation facility (ESRF)