We report persistently increased conduction in ZnO nanowires irradiated by ion beam with various ion energies and species. This effect is shown to be related to the already known persistent photo conduction in ZnO and dubbed persistent ion beam induced conduction. Both effects show similar excitation efficiency, decay rates, and chemical sensitivity. Persistent ion beam induced conduction will potentially allow countable (i.e., single dopant) implantation in ZnO nanostructures and other materials showing persistent photo conduction.
Zinc oxide and Aluminum Ferrite were prepared Chemical route. The samples were characterized by XRD and VSM. Simulation of M-H plots of Co/CoO thin films were performed. Effect of parameters was observed on saturation magnetization.
The Zn K-edge X-ray absorption spectroscopy has been used to investigate in situ the decomposition of zinc peroxide (ZnO$_2$) to zinc oxide (ZnO). Principal component and linear combination analyses of the EXAFS spectra have been employed to identify the phase composition of the oxide upon heating to 900$^\circ$C. Only the ZnO$_2$ phase has been found up to 180$^\circ$C, whereas only the nanocrystalline ZnO phase has occurred above 250$^\circ$C. Detailed structural information on the temperature dependence of the local environment of zinc atoms has been obtained using the reverse Monte Carlo s…
During a bioInspired crystallization process, incorporation of amino acids into the crystal structure of ZnO induces lattice strain that leads to linear bandgap shifts.
The mechanical properties of Cadmium Selenide (CdSe) nanowire is an emerging issue due to its application in semiconductor and optoelectronics industries. In this paper, we conducted molecular dynamics (MD) simulations to investigate the temperature-dependent mechanical properties and failure behavior of Zinc-Blende (ZB) CdSe nanowire under uniaxial tensile deformation. We employed Stillinger-Weber (SW) potential to describe the inter-atomic interactions. The effect of variation of temperatures (100 K-600 K), sizes, and crystal orientation on the tensile response of the CdSe nanowires is inves…
In this work we use density functional theory (DFT) to investigate the influence of semi-local exchange and correlation effects on the electronic and optical properties of zinc oxide. We find that the inclusion of such effects using the Tran-Blaha modified Becke-Johnson potential yields an excellent description of the electronic structure of this material giving energy band gap which is systematically larger than the one obtained with standard local functionals such as the generalized gradient approximation. The discrepancy between the experimental and theoretical band gaps is then significant…
The problem of detecting the ability of some metal oxides as photocatalysts is receiving considerable attention in the world. The studied zinc oxide is considered as one of the most utilized semiconductors, due to its direct band gap of 3.37 eV and a large exciton binding energy of 60 meV at room temperature. The characteristic formulation of Copper doped zinc oxide is implemented to obtain an improved adsorption kinetics and photocatalytic activity of zinc oxide photocatalyst capable of evolving estimated photoluminescence (PL) spectra of zinc oxide nanoparticles to explore the effect of Copp…
Competition between Ferrimagnetism and Magnetic Frustration in Zinc Substituted YBaFe4O7
用Zn取代YBaFe_4 O_7中的Fe，合成了属于“114”结构族的氧化物系列YBaFe_4-xZn_xO_7（0.40 < x < 1.50）。这些氧化物以六方对称（P63 mc）结晶，而不是立方对称（F-43 m）的YBaFe 4 O 7。重要的是，直流磁化表明，锌取代诱导亚铁磁性，相反的自旋玻璃行为的YBaFe 4 O 7。此外，a.c.磁化率测量表明，伴随着这些氧化物表现出自旋玻璃或团簇玻璃行为，随着锌含量的增加，其以亚铁磁性为代价而增加。亚铁磁性和磁挫折之间的这种竞争被解释在解除几何挫折，诱导磁有序，和阳离子无序，这有利于玻璃态。
Emerging technologies are demanding innovative properties of glasses. In this work, Cerium Oxide is used as a dopant in Zinc-Tellurite samples and its effects on the properties of the glass are investigated. Thermal analysis and x-ray diffraction confirmed the amorphous nature of all samples. The bivalent nature of Cerium is investigated spectroscopically and a strong redshift induced by the dopant is attributed to charge transfers O$^{2-}{\rightarrow}$Ce$^{4+}$, while the 4f-5d transition of Ce$^{3+}$ could not be identified in absorption or luminescence measurements. Yellow/red (570/650 nm) …
Band convergence and linearization error correction of all-electron GW calculations: The extreme case of zinc oxide
最近，Shih等人[Phys. Rev. Lett. 105，146401（2010）]公开了用非自洽GW近似计算的纤锌矿ZnO的理论带隙，其与实验惊人地一致，同时强烈偏离先前的研究。他们表明，需要大量的空带来收敛间隙。我们重新检查GW计算与全电位线性增强平面波方法，发现即使有3000带的带隙是不完全收敛。双曲线拟合用于外推到无限频带。此外，我们消除了线性化误差的高lying态与本地轨道。事实上，我们计算的带隙比以前的研究大得多，但比Shih等人的要小。
The exploration of new catalysts for the vapor-liquid-solid (VLS) synthesis of one-dimensional (1-D) materials promises to yield new morphologies and functionality. Here, we show, for the model ZnO system, that this possible using a semiconductor (Ge) catalyst. In particular, two unusual morphologies are described: twisted nanowires and twisted nanotubes, in addition to the usual straight nanowires. The twisted nanotubes show large hollow cores and surprisingly high twisting rates (up to 9o/μm), which cannot be easily explained through the Eshelby twist model. A combination of ex situ and in s…
The structural and electronic properties of tin oxide nanowires: an {\it ab initio} investigation
我们对金红石型氧化锡（SnO $_{x}$）纳米线的性质进行了{ \it ab initio}研究。我们计算了几种导线尺寸和表面小平面配置的导线属性，确定平衡几何形状，结合能和电子能带结构。结果允许建立缩放律的结构特性，在纳米线周长。结果还表明，表面态控制了纳米线的大部分电子性质。纳米线表面的氧掺入钝化了表面相关的电子态，由此产生的量子特性和标度律与纳米线内部的电子完全一致。此外，线表面中的氧掺入产生了自旋向上和向下电子的不平衡浓度，导致纳米线的磁性状态。
We study the influence of polarity on the binding and diffusion of single conjugated organic molecules on the inorganic (10-10) zinc oxide surface by means of all-atom molecular dynamics simulations at room temperature and above. In particular, we consider the effects of partial fluorination of the para-sexiphenyl (p-6P) molecule with chemical modifications of one head group (p-6PF2) or both (symmetric) head and tail (p-6PF4). Quantum-mechanical and classical simulations both result in consistent and highly distinct dipole moments and densities of the fluorinated molecules, which interestingly…
Zinc phosphide, Zn3P2, nanowires constitute prospective building blocks for next generation solar cells due to the combination of suitable optoelectronic properties and an abundance of the constituting elements in the Earths crust. The generation of periodic superstructures along the nanowire axis could provide an additional mechanism to tune their functional properties. Here we present the vapour-liquid-solid growth of zinc phosphide superlattices driven by periodic heterotwins. This uncommon planar defect involves the exchange of Zn by In at the twinning boundary. We find that the zigzag sup…
Heterostructures of Co-doped ZnO and Permalloy were investigated for their static and dynamic magnetic interaction. The highly Co-doped ZnO is paramagentic at room temperature and becomes an uncompensated antiferromagnet at low temperatures, showing a narrowly opened hysteresis and a vertical exchange bias shift even in the absence of any ferromagnetic layer. At low temperatures in combination with Permalloy an exchange bias is found causing a horizontal as well as vertical shift of the hysteresis of the heterostructure together with an increase in coercive field. Furthermore, an increase in t…
Growth driven phase transitions in Zinc Oxide nanoparticles through machine-learning assisted simulations
CEMES, CNRS and Université de Toulouse（图卢兹大学）；CNRS, Sorbonne Université, Institut des NanoSciences de Paris, UMR 7588（索邦大学）；Univ. Lille, CNRS, INRA, ENSCL, UMR 8207, UMET, Unité Matériaux et Transformations（里尔大学）
