開(kāi)一個(gè)新坑:每周至少分析三篇頂刊的寫(xiě)作思路带欢,來(lái)提升自己的寫(xiě)作能力。今天是1/3
通過(guò)構(gòu)建Sm摻雜的0 0.015的PIN-PZT樣品得到了很高的電致伸縮系數(shù)(8 × 10?16 m2 V?2)? ? 性能
1. 基本的思路:
第一步:Sm-PNZT 樣品的性能和其他樣品的對(duì)比
中心:M33在所有的弛豫鐵電體中性能最高
第二步:通過(guò)宏觀的TEM說(shuō)明看到的沉淀析出相和析出相之外的疇結(jié)構(gòu)
第三步:納米沉淀析出相的結(jié)構(gòu)極化矢量以及文字論述為什么能夠減小滯后
其實(shí)有圖表明了Sm摻雜之前存在滯后但還是放在了參考文獻(xiàn)當(dāng)中荧关,對(duì)比并不是這篇文章想說(shuō)的,而是對(duì)這個(gè)材料本身的論述才是這篇文章想要傳達(dá)的褂傀。
文字論述為什么能夠減小滯后:
1.?both the magnitude and angle of the polarization vectors continuously evolved from the outside to the center of the endotaxial nanoprecipitation.
2.?the polarization magnitude decreased to nearly zero at the central region, yielding a nonpolar state.
3. Such evolutions of the polarizations strongly break the long-range ferroelectric ordering, which results in a more flexible polarization configuration and further enhances the dielectric relaxation performance
Based on these observations, the domain structure was constructed as illustrated in Figure?3h, which can well explain the origin of the high electrostrain performance. In the matrix region, the PNRs with R and T symmetries are randomly distributed in the C matrix, providing a strong polarization response as well as a large strain under a relatively weak electric field. This is consistent with the role of PNRs in RFEs reported in previous studies.[16,39] However, the randomly distributed endotaxial nanoprecipitations feature a transitional ring region with a sharply changing polarization in terms of both direction and magnitude, indicating the weak constraint of the local crystallographic symmetry, and a nonpolar central region. Such endotaxial nanoprecipitations are essentially induced by the cooperation of the segregated A-site and B-site elements and are markedly different from the C phase nanoregions in the matrix, especially in terms of their behaviors under external electric fields. Specifically, the C phase nanoregions in the matrix are formed owing to the free energy fluctuation and the strong random electric field, and are highly polarizable under the electric field stimuli. In contrast, the nonpolar central region of the endotaxial nanoprecipitations caused by the enrichment of Sm3+ cations is difficult to polarize even by a strong electric field. As a result, the endotaxial nanoprecipitations with a nonpolar central region can provide a strong restoring force, which facilitates the transformation from a normal ferroelectric state to a relaxor state upon unloading. This results in a faster strain response to the external electric field, namely, a hysteresis-free strain response.
基于這些觀察忍啤,我們構(gòu)建了如圖3h所示的疇結(jié)構(gòu),可以很好地解釋高電應(yīng)變性能的起源仙辟。在矩陣區(qū)域同波,具有R和T對(duì)稱(chēng)的PNRs隨機(jī)分布在C矩陣中,在相對(duì)較弱的電場(chǎng)作用下叠国,PNRs具有較強(qiáng)的極化響應(yīng)和較大的應(yīng)變未檩。這與以往研究中報(bào)道的PNRs在rfe中的作用一致。[16,39]然而粟焊,隨機(jī)分布的胞內(nèi)納米沉淀物在方向和大小上極化急劇變化的過(guò)渡環(huán)區(qū)冤狡,表明局部晶體對(duì)稱(chēng)性約束較弱,中心區(qū)域?yàn)榉菢O性區(qū)域项棠。這種內(nèi)層納米沉淀物主要是由分離的a位和b位元素共同作用而形成的悲雳,與基體中的C相納米區(qū)明顯不同,特別是在外加電場(chǎng)作用下的行為香追。其中合瓢,基體中的C相納米區(qū)是由于自由能漲落和強(qiáng)隨機(jī)場(chǎng)形成的,在電場(chǎng)刺激下具有很強(qiáng)的極化性透典。相反晴楔,由于Sm3+離子的富集而形成的胞內(nèi)納米沉淀物的非極性中心區(qū)域即使在強(qiáng)電場(chǎng)作用下也難以極化迁央。結(jié)果表明,具有非極性中心區(qū)域的內(nèi)嵌納米沉淀物具有很強(qiáng)的還原力滥崩,有利于從正常鐵電態(tài)向弛豫態(tài)的轉(zhuǎn)變。這導(dǎo)致了對(duì)外部電場(chǎng)的更快應(yīng)變響應(yīng)讹语,即無(wú)遲滯應(yīng)變響應(yīng)钙皮。(其實(shí)這也可以說(shuō)是儲(chǔ)能性能提高的原因,如何在薄膜中構(gòu)建這種由成分偏析帶來(lái)的局部的非極性相的析出呢顽决?是不是也是一個(gè)重要的方向)
第四步:通過(guò)原位電場(chǎng)XRD證明外部的響應(yīng)來(lái)自于晶格的應(yīng)變
這一段實(shí)則是想建立外部應(yīng)變與內(nèi)部應(yīng)變的關(guān)系的一個(gè)手段短条,歸因于晶格應(yīng)變,
1. The lattice strain, calculated from the {200}pc peak shift in the 0° sector, was comparable to the macrostrain (Figure?4d), suggesting that the macrostrain mainly originated from the intrinsic lattice strain.
2才菠,By analyzing the evolution of the {200}pc peak in the 0° sector under the cyclic electric field (Figure? 4c), it was found that the peak shifted without any change in the peak profile when the electric field was applied and removed. This suggests that no noticeable macrodomain switching occurred during the electric field loading–unloading procedure.
3. In contrast, the peaks of {200}pc and {111}pc in the 45° sector (Figure? 4a,b) showed a negligible shift and profile change with the changing electric field, indicating the lack of phase transition.
4.?Therefore, the easy growth of the inhomogeneous PNRs into the long-range ferroelectric domains facilitates the intrinsic lattice strain of the Sm-PNZT?ceramic, leading to a significant response of the macrostrain under a weak electric field.
2. 啟發(fā)
頂刊AM并不需要嚴(yán)格的對(duì)比茸时,把一個(gè)樣品的故事講清楚也行
并不需要嚴(yán)格的證明,而是言之有物赋访,言之成理可都,看上去沒(méi)有邏輯硬傷即可。