本文报道了用非磁性金属Mg取代Co的方法来增强$_4$-Nb-$_2$-O-$_9$的磁电耦合的实验研究。一系列单晶Co $_{4-x}$ Mg-$_x$-Nb $_2$ O $_9$（x=0，1，2，3）具有单相刚玉型结构，劳厄斑和尖锐的X射线衍射峰证实了合成样品的良好质量和晶体学取向。尽管Mg取代晶体的Neel温度（$T_N$）从纯Co $_4$ Nb $_2$ O $_9$的27 K分别略微降低到Co $_3$ MgNb $_2$ O $_9$和Co $_2$ Mg $_2$ Nb $_2$ O $_9$的19 K和11 K，但当x=1时，通过Mg取代使ME耦合加倍增强。对于电极化的强度（磁化）的磁场（电场）控制，Co $_3$ MgNb $_2$ O $_9$的ME系数$α_{ME}$被测量为12.8 ps/m（13.7 ps/m）。这些结果表明Mg取代的Co $_{4-x}$ Mg $_x$ Nb $_2$ O $_9$（x=1）可以作为一种潜在的候选材料用于未来的逻辑自旋电子学和逻辑器件。
英文摘要：
We report experimental studies on enhancing the magnetoelectric (ME) coupling of Co$_4$Nb$_2$O$_9$ by substitution of non-magnetic metal Mg for Co. A series of single crystal Co$_{4-x}$Mg$_x$Nb$_2$O$_9$ (x=0, 1, 2, 3) with a single-phase corundum-type structure are synthesized by the optical floating zone method, and the good quality and crystallographic orientations of the synthesized samples are confirmed by Laue spots and sharp XRD peaks. Although the Neel temperature ($T_N$) of the Mg substituted crystals are slightly decreased from 27 K for pure Co$_4$Nb$_2$O$_9$ to 19 K and 11 K for Co$_3$MgNb$_2$O$_9$ and Co$_2$Mg$_2$Nb$_2$O$_9$, respectively, the ME coupling is double enhanced by Mg substitution when x=1. For the magnetic field (electric field) control of electric polarization (magnetization), the ME coefficient $α_{ME}$ of Co$_3$MgNb$_2$O$_9$ is measured to be 12.8 ps/m (13.7 ps/m). These results indicate that the Mg substituted Co$_{4-x}$Mg$_x$Nb$_2$O$_9$ (x=1) could serve as a potential material candidate for applications in future logic spintronics and logic devices.
Modifying the magnetoelectric coupling in TbMnO$_3$ by low-level Fe$^{3+}$ substitution
本文报道了Fe $^{3+}$对TbMn $_{1-x}$ Fe $_x$ O $_3$（$x=0$，0.02和0.04）中的静态和动态磁电耦合的影响。阳离子取代对竞争性磁相互作用之间的平衡有很大的影响，因此，在低温下对磁性结构和铁电相的稳定性有很大的影响。低位的电磁振子激发激活TbMnO $_3$中的摆线调制的反铁磁和铁电相，而它被观察到TN的Fe取代的化合物，静态和动态磁电耦合的不同机制。第二个电活性激发近40厘米$^{-1}$解释通过Tb 3+晶体场效应。这种激发被观察到室温，并表现出显着的15厘米$^{-1}$降频冷却Fe取代的化合物。电磁振子和晶体场激发被发现耦合到极性声子的频率高达250厘米$^{-1}$。拉曼光谱显示纯TbMn O $_3$在TN以下存在自旋-声子耦合，但TbMn $_{0.96}$ Fe $_{0.04}$ O $_3$的自旋-声子耦合开始温度随Fe浓度的增加而升高，达到100 K。自旋-声子耦合和晶体场激发，耦合到氧运动的T-依赖性的磁化率TN以上的异常占。
Magnetoelectric Coupling in Nickel-Cobalt Ferrite and Lanthanum Ferrite Heterostructure Composites: Experimental Evidence and Simulation-Driven Insights
Enhancing Quasi-Two-Dimensional Electronic Structure in Bi2O2Se via Chlorine Substitution
ShanghaiTech University（上海科技大学）；Nanjing University（南京大学）；Diamond Light Source（钻石光源）；Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences（中国科学院上海高级研究院同步辐射实验室）；National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences（中国科学院上海微系统与信息技术研究所国家集成电路材料重点实验室）
Enhancing Hydrogen Adsorption Ability of MOF-5 with Metal Node Exchange and Linker Functionalisation
Carl von Ossietzky Universität Oldenburg（奥尔登堡卡尔·冯·奥西茨基大学）；Friedrich-Schiller Universität Jena（耶拿弗里德里希·席勒大学）；Université de Montpellier, CNRS, ENSCM（蒙彼利埃大学，法国国家科学研究中心，国立化学学院）
Enhancing Chemical Stability and Photovoltaic Properties of Highly Efficient Nonfullerene Acceptors by Chalcogen Substitution: Insights from Quantum Chemical Calculations
