arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2012.04319cond-mat.mtrl-sci
收藏

稀土对Na $_{0.5}$ Bi $_{0.5}$ TiO $_3$体系物理性质的影响:密度泛函理论研究

Rare-earth effect on the physical properties of Na$_{0.5}$Bi$_{0.5}$TiO$_3$ system: A Density Functional Theory investigation

Manal Benyoussef, Halima Zaari, Jamal Belhadi, Youssef El Amraoui, Hamid Ez-Zahraouy, Abdelilah Lahmar, Mimoun El Marssi

摘要:

采用基于自旋极化密度泛函理论的全势能线性缀加平面波(FP-LAPW)方法,在第一性原理计算框架下研究了Na $_{0.5}$(Bi $_3$ /4 RE $_{1/4}$)$_{0.5}$ TiO $_3$(RENBT,RE = Nd,Gd,Dy,Ho)化合物.结合电荷密度分布和Ti K边X-射线吸收光谱表明,RENBT组合物具有高极化值伴随着较高的TiO $_6$失真,DyNBT,NdNBT化合物。通过磁滞回线的采集,从实验上证实了稀土元素对极化的影响。对化合物的电子性质的研究突出了由于稀土元素的4f轨道效应而出现的磁化。此外,化学有序性的研究表明,纯组分的短程化学有序和增加的A位无序的镝掺杂的NBT系统。增加的无序可以说明RE掺杂的组合物中增加的弛豫性质。

英文摘要:

Na$_{0.5}$(Bi$_3$/4RE$_{1/4}$)$_{0.5}$TiO$_3$ (RENBT, RE = Nd, Gd, Dy, and Ho) compounds were investigated in the framework of first-principles calculations using the full potential linearized augmented plane wave (FP-LAPW) method based on the spin-polarized density functional theory implemented in the WIEN2k code. Combined charge density distribution and Ti K-edge x-ray absorption spectra revealed that the RENBT compositions with high polarization values were accompanied by a higher TiO$_6$ distortion, DyNBT, and NdNBT compounds. The effect of the rare-earth elements on the polarization were confirmed experimentally with the collection of the hysteresis loops. The investigation of the electronic properties of the compounds highlighted the emergence of a magnetization owing to the 4f orbital effect of the rare-earth elements. Besides, the investigation of the chemical ordering showed a short-range chemical ordering for the pure composition and an increased A-site disorder for dysprosium doped NBT system. The increased disorder may speak for increased relaxor properties in the RE doped compositions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑