Accurate temperature measurement is a long-standing challenge in laser-heated diamond anvil cell (LH-DAC) experiments, where the reported temperature must reflect the true thermal state of the region being probed. Conventional single-point spectro-radiometry collects emission from one localized spot and fits a single temperature, leaving it blind to spatial variations and to wavelength-dependent optical distortions in the imaging path. Existing 2D approaches based on multi-color imaging or peak scaling provide spatial information but do not explicitly model or correct these chromatic… more
Valery I. Levitas, Anson Marston Distinguished Professor in Engineering and holder of the Murray Harpole Chair in Engineering in the Departments of Aerospace and Mechanical Engineering at Iowa State University, and a frequent APS user, recently published a comprehensive review paper, “Strain-induced phase transformations, chemical reactions, microstructure evolution, and severe plastic deformations under high pressure,” in Progress in Materials Science, 2026, Vol. 158, 101625, 118 pages.
It is known that processes involving severe plastic deformation (SPD), phase… more
The refractory transition metal Rhenium (Re) is known to exist in a hexagonal close packed (hcp) phase right up to its high melting temperature of 3459 K and cubic phases have not been reported in rhenium rich alloys at ambient conditions. University of Alabama at Birmingham (UAB) researchers report on an unusual observation of pressure stabilized dual cubic phases in a high entropy alloy based on Re (https://journals.aps.org/prmaterials/abstract/10.1103/8smt-nygp). The structural… more
Researchers from the University of Houston and its Texas Center for Superconductivity collaborated with researchers from Argonne at the Advanced Photon Source to set a record superconducting transition temperature up to 151 K (at pressures in the range 10 – 30 GPa) in HgBa2Ca2Cu3O8+d. The more impressive part of this work is that they report a pressure quenching protocol (PQP) that allows them to quench the high-pressure phase to complete pressure release and record ambient-pressure high-temperature superconductivity. This nonequilibrium strategy for recovering novel,… more
Understanding the kinetics of pressure-induced phase transformations requires experiments that can simultaneously control both pressure and temperature on timescales relevant to diffusional processes, typically 1 to 100 ms. While piezoelectrically driven dynamic diamond anvil cells (dDACs) excel at providing rapid, precisely controlled compression over many orders of magnitude in pressurization rate, their use at elevated temperatures has been severely limited by a geometric incompatibility: existing dDAC designs are too long to fit within the optical systems required for double-sided… more
High-entropy alloys have attracted growing attention due to their unusual phase stability, mechanical resilience, and emergent electronic properties under extreme conditions. While configurational entropy favors chemically disordered solid solutions, controlled pathways to introduce long-range chemical order in multicomponent alloys remain largely unexplored – particularly under simultaneous high pressure and high temperature.
In recent work, the high-pressure research group led by Prof. Yogesh K. Vohra at the University of Alabama at Birmingham (UAB) employed… more
In the recently published and highlighted work by Phys. Rev. B, the authors identified the thermodynamic mechanism behind the pressure-induced Invar effect in the Fe₆₈Pd₃₂ alloy, using synchrotron x-ray diffraction, nuclear resonant scattering, and neutron spectroscopy. Between 4 and 11 GPa, the material shows zero or negative thermal expansion as opposing contributions from phonon and magnetic entropies exactly cancel, even though each individually increases under pressure. The results reveal a small but measurable spin–phonon interaction (≈ 2 meV per atom) and demonstrate that the… more
Creating and understanding new permanent magnets requires an understanding effect of orbital angular momentum on coercivity. Permanent magnets are at the core of technologies ranging from energy generators to energy storage. The next generation of magnetic technology not only needs discovering new magnetic materials but also being able to tune the magnetic properties. Pressure enables tuning inter-atomic spacing and therefore their interactions much better than any other variable such as temperature or composition. Synchrotron based, in-situ measurements of structure and magnetic… more