正交晶系
四方晶系
相(物质)
反铁电性
结晶学
铁电性
凝聚态物理
材料科学
背景(考古学)
Crystal(编程语言)
晶体结构
空间组
化学
X射线晶体学
衍射
化学物理
物理
电介质
光学
光电子学
量子力学
古生物学
生物
计算机科学
程序设计语言
作者
Luis Azevedo Antunes,Richard Ganser,Ruben Alcala,Thomas Mikolajick,Uwe Schroeder,Alfred Kersch
摘要
Perturbing tetragonal HfO2 supercells in simulation with dopants or interstitial oxygen in the context of the ferroelectric Pca21 No. 29 (oIII-phase) formation frequently leads to an unexplored, lower energetic orthorhombic crystal phase with space group Pnma No. 62 (oV-phase). The crystal structure is inequivalent to cottunite oII-phase with the same space group but is closely related to the second ferroelectric Pmn21 No. 31 (oIV-phase) space group, as antipolar alignment. To explore the possibility of oIV- or oV-phase formation, we calculate the free energy in harmonic approximation and the energy landscape. Starting from the tetragonal P42/nmc No. 137 phase (t-phase), according to energy and activation barrier, the formation of the oV-phase is more favorable than that of the oIV-phase. Furthermore, exploring the energy landscape of the oIV–oV system, we find possible antiferroelectric-like behavior in HfO2 and Hf0.5Zr0.5O2, but not in ZrO2. We propose the formation of an oV-phase fraction as a possible structural explanation for a contribution to the wake-up phenomenon in HfO2. X-ray diffraction results on 10 nm Hf1−xZrxO2 thin films with varying Zr content are consistent with the claim.
科研通智能强力驱动
Strongly Powered by AbleSci AI