2025-10-20 ペンシルベニア州立大学（Penn State)
Three of the seven newly synthesized high-entropy oxide ceramic pellets are pictured here. Credit: David Kubarek/Penn State. All Rights Reserved.
＜関連情報＞
- https://www.psu.edu/news/earth-and-mineral-sciences/story/simple-stabilizing-solution-leads-seven-new-ceramic-materials
- https://www.nature.com/articles/s41467-025-63567-z
熱力学に着想を得た高エントロピー酸化物合成 Thermodynamics-inspired high-entropy oxide synthesis
Saeed S. I. Almishal,Matthew Furst,Yueze Tan,Jacob T. Sivak,Gerald Bejger,Joseph Petruska,Sai Venkata Gayathri Ayyagari,Dhiya Srikanth,Nasim Alem,Christina M. Rost,Susan B. Sinnott,Long-Qing Chen & Jon-Paul Maria
Nature Communications Published:02 September 2025
DOI:https://doi.org/10.1038/s41467-025-63567-z
Abstract
High-entropy oxide (HEO) thermodynamics transcend temperature-centric approaches, spanning a multidimensional landscape where oxygen chemical potential plays a decisive role. Here, we experimentally demonstrate how controlling the oxygen chemical potential coerces multivalent cations into divalent states in rock salt HEOs. We construct a preferred valence phase diagram based on thermodynamic stability and equilibrium analysis, alongside a high throughput enthalpic stability map derived from atomistic calculations leveraging machine learning interatomic potentials. We identify and synthesize seven equimolar, single-phase rock salt compositions incorporating Mn, Fe, or both, as confirmed by X-ray diffraction and fluorescence. Energy-dispersive X-ray spectroscopy confirms homogeneous cation distribution, whereas X-ray absorption fine structure analysis reveals predominantly divalent Mn and Fe states, despite their inherent multivalent tendencies. Ultimately, we introduce oxygen chemical potential overlap as a key complementary descriptor for predicting HEO stability and synthesizability. Although we focus on rock salt HEOs, our methods are chemically and structurally agnostic, providing a broadly adaptable framework for navigating HEOs thermodynamics and enabling a broader compositional range with contemporary property interest.
