The broadening and optical parameters of TiO2/SiO2 transition layers depending on the ion energy have been investigated using the Rutherford Backscattering Spectrometry (RBS) and Ellipstrometry Spectroscopy (ES) methods. The TiO2/SiO2 samples were irradiated by Xe+ ions with energies of 100, 150, 200 and 250 keV. The depth profiles of the elements determined by the RBS spectra show the structure and thickness of the TiO2/SiO2 transition layers before and after implantation. We have found that the thickness of the transition region between the TiO2 and SiO2 layers increases with the increasing incident ion energy. This phenomenon indicates an increasing amount of atomic mixing at the TiO2/SiO2 interface. In addition, the variation of transition layers could be explained by defect depth profiles and ions energy transferred in the mixed layers by means of SRIM calculations. The thickness obtained from the RBS is in good agreement with that measured using the ES method. Based on these obtained results, we have also investigated the optical constants of implanted and non-implanted TiO2/SiO2 structures. The wave forms measured with varying incident angles suggest that the measurements were made close to near the main principle point. The yields of ψand δbands vary at different incident angles, is associated with interference processes of the light reflected from the structures examined. The refractive index and the extinction coefficient were found to increase after implantation taking place up to 200-keV Xe and then decrease at 250 keV.
In this communication we report the fluorine ion dynamics in mixed alkali oxyfluro vanadate glasses. We have measured the electrical conductivity using impedance spectroscopy technique Room temperature conductivity falls to 5 orders of magnitude from its single alkali values at 33 mol% of rubidium concentration. We have also estimated the distance between similar mobile ions using the density values. Assuming this distance as the hopping distance between the similar ions we have estimated the anionic (Fluorine ion in our case) conductivity. It is observed that the fluorine ion dynamics mimics …
Computation of Madelung Energies for Ionic Crystals of Variable Stoichiometries and Mixed Valencies and their application in Lithium-ion battery voltage modelling
静电能（马德隆能）是离子晶体内聚能的主要组成部分。这些材料的若干物理化学性质取决于它们的静电能对各种施加的热、电和机械应力的响应。在本研究中，已经开发了一种方法的基础上Ewalds技术，计算离子晶体如LixMn 2 O 4与可变化学计量和混合价的离子-离子相互作用所产生的静电能。首次提出了该方法在计算尖晶石阴极锂离子电池电压中的一个有趣应用。本文还讨论了本计算方法与现有方法相比的优点。
Ionic-instability induced color tuning in lead-based, mixed-halide perovskites
Chromatic Lighting（色度照明）；University of Notre Dame, Department of Physics and Astronomy（圣母大学物理与天文系）；University of Notre Dame, Department of Chemistry and Biochemistry（圣母大学生物化学系）；I-LAMP and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore（天主教大学数学与物理系及I-LAMP）；PY Materials（PY材料公司）；Notre Dame Radiation Laboratory（圣母大学辐射实验室）
New emerging disciplines such as Nanoionics and Iontronics are dealing with the exploitation of mesoscopic size effects in materials, which become visible (if not predominant) when downsizing the system to the nanoscale. Driven by the worldwide standardisation of thin film deposition techniques, the access to radically different properties than those found in the bulk macroscopic systems can be accomplished. This opens up promising approaches for the development of advanced microdevices, by taking advantage of the nanostructural deviations found in nanometre sized, interface dominated material…
In complex oxide heteroepitaxy, strain engineering is a powerful tool to obtain phases in thin films that may be otherwise unstable in bulk. A successful example of this approach is mixed phase bismuth ferrite (BiFeO3) epitaxial thin films. The coexistence of a tetragonal-like (T-like) matrix and rhombohedral-like (R-like) striations provides an enhanced electromechanical response, along with other attractive functional behaviors. In this paper, we compare the energetics associated with two thickness dependent strain relaxation mechanisms in this system: domain walls arising from monoclinic di…
Mixed eldfellite compounds \ce{Na(Fe_{1/2}M_{1/2})(SO4)2} (M = Mn, Co, Ni): A new family of high electrode potential cathodes for the sodium-ion battery
Contrary to the common belief that light-induced halide ion segregation in a mixed halide al-loy occurs within the illuminated area, we find that the Br ions released by light diffuse away from the area, which generates a counter-balancing Coulombic force between the anion deficit and surplus region, together resulting in a macro/mesoscopic size anion ring surrounding the center, showing a photoluminescence ring. Upon removing the illumination, the displaced anions return to the illuminated area, and the restoring force leads to a damped ultra-low-frequency oscillatory ion motion, which may be…
Quantitative Analysis of Light Induced Ion Segregation in Mixed-Halide Perovskites
Charles University（查理大学）；Czech Technical University in Prague（捷克布拉格工业大学）；Masaryk University（马萨里克大学）；Institute of Physics, Czech Academy of Sciences（捷克科学院物理研究所）
Magnetic anisotropy plays an essential role in information technology applications of magnetic materials, providing a means to retain the long-term stability of a magnetic state in the presence of thermal fluctuations. Anisotropy consists of a single-ion contribution stemming from the crystal structure and two-ion terms attributed to the exchange interactions between magnetic atoms. A lack of robust theory crucially limits the understanding of the temperature dependence of the anisotropy in pure two-ion and mixed single-ion and two-ion systems. Here, we use Green's function theory and atomisti…
A new nanofibrous material, consisting of a conductive carbon core and an external layer made of vanadium oxide, has been studied as a cathode for aluminium-ion batteries. The material enables a mixed-ion intercalation mechanism, resulting in the alternating insertion of $\text{Al}^{3+}$ and $\text{AlCl}_4^-$ in the $\text{V}_2\text{O}_5$ and carbon layers, respectively. This is a highly desirable feature for cathode materials which may increase the energy density of future batteries by optimising the utilisation of the electrolyte.
We describe a method to automatically generate an ion implantation recipe, a set of energies and fluences, to produce a desired defect density profile in a solid using the fewest required energies. We simulate defect density profiles for a range of ion energies, fit them with an appropriate function, and interpolate to yield defect density profiles at arbitrary ion energies. Given $N$ energies, we then optimize a set of $N$ energy-fluence pairs to match a given target defect density profile. Finally, we find the minimum $N$ such that the error between the target defect density profile and the …
pH Regulates Ion Dynamics in Carboxylated Mixed Conductors
Lehigh University（利哈伊大学）；University of Washington（华盛顿大学）；Georgia Institute of Technology（佐治亚理工学院）；Stanford Synchrotron Radiation Lightsource SLAC National Accelerator Laboratory（斯坦福同步辐射光源 SLAC 国家加速器实验室）
