The 9th International Conference on Matter and Radiation at Extremes (ICMRE2026) ( ICMRE2026)

70 / 2026-03-26 12:53:09

Phase transition sequence of binary and pseudo-binary oxides upon compression

high pressure,Phase transition,binary oxides

High-Pressure Materials Science > Static High-Pressure Physics

To reveal the pressure induced phase transitions sequence patterns in several typical binary oxide and pseudo-binary oxide systems, the in situ high pressure synchrotron X-ray diffraction (XRD) experiments were carried out. The potential universal phase transitions pathway was proposed upon strong compression, i. e. when pressure reach region of 100 ~ 900 GPa. Other type of modifications to tune the phase stability and transition behaviours under high pressure will be introduce. Such as the gradient doping of Nb element to nano CeO₂, inducing a sluggish continuing transition to orthorhombic phase during compression and enhanced the higher pressure phase in decompression process. This unconventional phase transition behaviour deepens our understanding of the physical and chemical properties of doped nanomaterials. Another route of modification is single-phase oxides composed of muti-elements developed from the concept of high entropy alloys. The compositional flexibility provides infinite possibilities for the application of high entropy oxides (HEOs) in various fields. By taking advantage of the potential cocktail effect of HEOs, we designed and synthesized rutile-type HEO by solid-phase reaction method. to reveal their disorder, local lattice strain, and entropy features. Although the structural transition under high pressure of conventional rutile TiO₂ has been extensively studied, the influence of multiple composition on the structural transition pathways of rutile-type HEO under high pressure conditions offers us new opportunity to discover the new phase transition sequence upon compression.