论文标题
拉曼和红外光谱的第一原理计算，用于相识别和应变校准
First-principles Calculations of Raman and Infrared Spectroscopy For Phase Identification and Strain Calibration of Hafnia
论文作者
论文摘要
使用密度功能扰动理论（DFPT），我们计算了Hafnia polymorphs的声音频率，拉曼和IR活动（P4 $ _ {2} $ NMC，PCA2 $ _ {1} $，PMN2 $ _ {1} $ {1} $，PBCA OI，Brookokite，Brookite and Baddeledeley and baddeley and caseififitifienciention。我们研究了拉曼和IR活性在外延菌株方面的演变，并提供了频率差异的图，这是实验校准和样品应变状态的应变的函数。我们发现了不同hafnia polymorphs的拉曼签名：$ω（a_ {1g}）= 300 $ cm $^{ - 1} $ for P4 $ _ {2} $ _ {2} $ nmc，$ω（a_ {1}） $ω（b_ {2}）= 693 $ cm $^{ - 1} $ for pmn2 $ _ {1} $，$ω（a_ {g}）= 513 $ cm $^{ - 1} $ for pbca（oi），$ω（oi），$ω（a_ _ _ {g} $ for for for for for for for for for for for for for for for for for for for for for for for for for， $ω（a_ {g}）= 496 $ cm $^{ - 1} $ for Baddeleyite。我们还确定了拉曼$ b_ {1g} $模式，偶极矩的反相振动，（$ω（b_ {1g}）= 758 $ cm $ $ cm $^{ - 1} $ for oi，$ω（b_ {1g}）= 784 $ cm $ $ cm $^{ - 1}我们计算了纵向光学（LO）和横向光学（TO）模式（$δ{ω_ {\ text {lo-text {lo-tox}}（a^{z} _ {1}} = 255 $ cm $ cm $ cm $^{ - 1} $ in PCA2 $ _ {1} $，以及$δ{ω_ {\ text {lo-to}}（a_ {1}）} = 263 $ cm $^{ - 1} $在PMN2 $ _ {1} $中的顺序与perovskite ferroelectrics相同的顺序，并与它们相关，并与它们相关，并将其与Anomalalial Bornal Bornal Bornal Bornal Bornal Pursment Portom Portim Porce at Hf Att Att Att Att （$ z^{*}（\ text {hf}）= 5.54 $）。
Using density functional perturbation theory (DFPT) we computed the phonon frequencies, Raman and IR activities of hafnia polymorphs (P4$_{2}$nmc, Pca2$_{1}$, Pmn2$_{1}$, Pbca OI, brookite, and baddeleyite) for phase identification. We investigated the evolution of Raman and IR activities with respect to epitaxial strain and provide plots of frequency differences as a function of strain for experimental calibration and identification of the strain state of the sample. We found Raman signatures of different hafnia polymorphs: $ω(A_{1g})=300$ cm$^{-1}$ for P4$_{2}$nmc, $ω(A_{1})=343$ cm$^{-1}$ for Pca2$_{1}$, $ω(B_{2})=693$ cm$^{-1}$ for Pmn2$_{1}$, $ω(A_{g})=513$ cm$^{-1}$ for Pbca (OI), $ω(A_{g})=384$ cm$^{-1}$ for brookite, and $ω(A_{g}) = 496$ cm$^{-1}$ for baddeleyite. We also identified the Raman $B_{1g}$ mode, an anti-phase vibration of dipole moments, ( $ω(B_{1g}) = 758$ cm$^{-1}$ for OI, $ω(B_{1g})= 784$ cm$^{-1}$ for brookite) as the Raman signature of antipolar Pbca structures. We calculated a large splitting between longitudinal optical (LO) and transverse optical (TO) modes ($Δ{ω_{\text{LO-TO}}(A^{z}_{1})}=255$ cm$^{-1}$ in Pca2$_{1}$, and $Δ{ω_{\text{LO-TO}}(A_{1})}=263$ cm$^{-1}$ in Pmn2$_{1}$) to the same order as those observed in perovskite ferroelectrics, and related them to the anomalously large Born effective charges of Hf atoms ($Z^{*}(\text{Hf}) = 5.54$).
