@article{QIAN2026, 
author = {Chao QIAN and Wenming QI and Abliz MATTURSUN and Qingyang HU and Yuanyuan WANG and Hongliang DONG and Bin CHEN},
title = {Raman Scattering Study of Lattice Dynamics and Phase Transitions in Layered Perovskite Sr2Ta2O7 Ceramics under High Pressure},
year = {2026},
journal = {Chinese Journal of High Pressure Physics},
volume = {40},
number = {10},
keywords = {high-pressure, perovskite, phase transition, Raman spectroscopy},
url = {https://www.sciopen.com/article/10.11858/gywlxb.20251269},
doi = {10.11858/gywlxb.20251269},
abstract = {The strontium tantalate Sr2Ta2O7 is a ceramic with an orthogonal Cmcm space group. Due to its potential applications in the field of multiferroics, it has become a research hotspot in recent years. However, the regulatory mechanism and phase transition behavior of hydrostatic pressure on its complex lattice structure remain unclear, which, to some extent, limits the in-depth understanding of the “structure-property” relationship of this material. This study systematically investigates the lattice dynamic response characteristics of orthogonal Cmcm Sr2Ta2O7 under high pressure up to 30 GPa by using in-situ high-pressure Raman spectroscopy, marking the highest pressure on this system to date. The results manifest that when the pressure reaches 5 GPa, significant changes occur in the Raman vibrational modes of the material. This phenomenon is attributed to a commensurate-to-incommensurate structural transition induced by symmetry breaking, consistent with previous research findings on Sr2Ta2O7. As the pressure further increasing to 20 GPa, a second phase transition may occur, which is identified as a first-order phase transition closely related to lattice disordering. However, the specific crystal structure of this high-pressure phase remains to be further confirmed in future studies. The Raman spectroscopy analysis suggests that the structural distortion of this high-pressure phase may follow a transformation pathway from orthogonal to monoclinic.}
}