Using the same pressure cell, it enables experiments performed at large-scale synchrotron facilities to be combined with high-pressure optical measurements carried out in the laboratory, in particular using nonlinear optical microscopy. The device integrates in situ pressure measurement by fluorescence directly within a second-harmonic generation (SHG) microscope, allowing precise and continuous monitoring of experimental conditions. Its design and implementation rely on instrumental developments in optics, mechanics, and measurement methodology carried out at IPCMS. This setup made it possible to reveal ferroelectric phase transitions induced by hydrostatic pressure up to 60 GPa in KNbO₃, a reference ferroelectric perovskite. Published in Physical Review Letters, this work is the result of a collaboration between the University of Luxembourg, Institut Néel, and the synchrotrons SOLEIL and ESRF. It opens new perspectives for multimodal studies of ferroelectric materials under extreme conditions.
Référence
Shoker et al., Re-emergence of a Polar Instability at High Pressure in KNbO3, Phys. Rev. Lett. 136, 056101 (2026) https://doi.org/10.1103/vwp9-tr7b < hal-05206803>
Contact Boris Croes Boris.Croes@ipcms.unistra.fr (Postdoc, IPCMS)
