"Structural transition and amorphization in compressed α − Sb2O3 "

Zhao Zhao: Qiaoshi Zeng, Haijun Zhang, Shibing Wang, Shigeto Hirai, Zhidan Zeng, and Wendy L. Mao; Phys. Rev. B 91, 05/27/15.

Additional Authors: Qiaoshi Zeng, Haijun Zhang, Shibing Wang, Shigeto Hirai, Zhidan Zeng, and Wendy L. Mao

Abstract:

Sb2O3-based materials are of broad interest in materials science and industry. High-pressure study using diamond anvil cells shows promise in obtaining new crystal and electronic structures different from their pristine states. Here, we conducted in situ angle dispersive synchrotron x-ray-diffraction and Raman spectroscopy experiments on α−Sb2O3 up to 50 GPa with neon as the pressure transmitting medium. A first-order structural transition was observed in between 15 and 20 GPa, where the cubic phase I gradually transformed into a layered tetragonal phase II through structural distortion and symmetry breaking. To explain the dramatic changes in sample color and transparency, we performed first-principles calculations to track the evolution of its density of states and electronic structure under pressure. At higher pressure, a sluggish amorphization was observed. Our results highlight the structural connections among the sesquioxides, where the lone electron pair plays an important role in determining the local structures.