Irradiation induced effects on Ni3N/Si bilayer system
TL;DR: In this article, the irradiation effect in Ni 3 N/Si bilayers induced by 100 MeV Au ions at fluence 1.5 × 10 14 ǫ cm 2 was investigated at room temperature.
About: This article is published in Vacuum.The article was published on 2009-08-11. It has received 12 citations till now. The article focuses on the topics: X-ray photoelectron spectroscopy & Thin film.
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TL;DR: A review of ion beam modifications at various solids, thin films, and multilayered systems covering wider energy ranges including the older basic concepts is given in this paper. But the results reveal that the ion-solid interaction physics provides a unique way for controlling the produced defects of the desired type at a desired location.
242 citations
TL;DR: The high efficiency of rationally-designed Ni3N0.85 demonstrates the effectiveness of the d-band tuning strategy to de-velop low-activation-energy catalysts and to promote the atomic understanding of polysulfides conversion in Li-S batteries.
Abstract: Slow kinetics of polysulfide conversion reactions lead to severe issues for lithium-sulfur (Li-S) batteries, for example, low rate capability, polysulfide migration, and low Coulombic efficiencies. These challenges hinder the practical applications of Li-S batteries. In this study, we proposed a rational strategy of tuning the d-band of catalysts to accelerate the conversion of polysulfides. Nitrogen vacancies were engineered in hexagonal Ni3N (space group P6322) to tune its d-band center, leading to the strong interaction between polysulfides and Ni3N. Because of the greater electron population in the lowest occupied molecular orbital of Li2S4, the terminal S-S bonds were weakened for breaking. Temperature-dependent experiments confirm that Ni3N0.85 demonstrates a much low activation energy, thereby accelerating the conversion of polysulfides. A Li-S cell using Ni3N0.85 can deliver a high initial discharge capacity of 1445.9 mAh g-1 (at 0.02 C) and low decay per cycle (0.039%). The Ni3N0.85 cell can also demonstrate an initial capacity of 1200.4 mAh g-1 for up to 100 cycles at a high loading of 5.2 mg cm-2. The high efficiency of rationally designed Ni3N0.85 demonstrates the effectiveness of the d-band tuning strategy to develop low-activation-energy catalysts and to promote the atomic understanding of polysulfide conversion in Li-S batteries.
178 citations
TL;DR: In this article, a novel Ni3N/graphene nanocomposite of small Ni 3N nanoparticles anchoring on the reduced graphene oxide nanosheets has been successfully synthesized.
Abstract: A novel Ni3N/graphene nanocomposite of small Ni3N nanoparticles anchoring on the reduced graphene oxide nanosheets has been successfully synthesized. Due to the quite small size of Ni3N nanocrystals, the surface for faradic redox reaction of pseudocapacitive materials dramatically increases. The main issue of the volume change obstructing the pseudo-supercapacitor performance is concurrently resolved by the tight attachment of Ni3N nanoparticles with flexible texture. Importantly, the two-step oxidation/reduction reaction between Ni(I) and Ni(III) endows this nanocomposite with large capacitance by providing more faradic charge. The kind of electrode material behaves excellently both in three-electrode and asymmetric supercapacitors. The biggest specific capacitance reaches to 2087.5 F g(-1) (at 1 A g(-1)), and its asymmetric supercapacitor cell with ethylene glycol modified RGO as negative electrode has a high energy density (50.5 W h kg(-1) at 800 W kg(-1)). The cell capacitance retention exceeds 80% after 5000 cycles at different high current densities, showing its promising prospects for high-energy supercapacitors.
106 citations
TL;DR: In this article, a brief review discusses recently published chemical reports that focus on the controlled synthesis of nickel nitride and its composites, such as thermal, structural, and magnetic properties.
41 citations
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TL;DR: The role of implantation defects, the effect of annealing, concentration dependent effects, and optical activation are discussed and compared for different Er-doped thin film photonic materials.
Abstract: Erbium doped materials are of great interest in thin film integrated optoelectronic technology, due to their Er3+ intra-4f emission at 1.54 μm, a standard telecommunication wavelength. Er-doped dielectric thin films can be used to fabricate planar optical amplifiers or lasers that can be integrated with other devices on the same chip. Semiconductors, such as silicon, can also be doped with erbium. In this case the Er may be excited through optically or electrically generated charge carriers. Er-doped Si light-emitting diodes may find applications in Si-based optoelectronic circuits. In this article, the synthesis, characterization, and application of several different Er-doped thin film photonic materials is described. It focuses on oxide glasses (pure SiO2, phosphosilicate, borosilicate, and soda-lime glasses), ceramic thin films (Al2O3, Y2O3, LiNbO3), and amorphous and crystalline silicon, all doped with Er by ion implantation. MeV ion implantation is a technique that is ideally suited to dope these materials with Er as the ion range corresponds to the typical micron dimensions of these optical materials. The role of implantation defects, the effect of annealing, concentration dependent effects, and optical activation are discussed and compared for the various materials.
1,089 citations
01 Mar 1980
TL;DR: In this article, a formulation explicite de l'influence des rugosites ainsi que des variations locales de constante dielectrique n2 (dues par exemple a modification de composition ou de compacite) sur la reflexion rasante d'un faisceau de rayons X monochromatique, dans la mesure ou les rugosite relevent d'une distribution gaussienne and a condition that n2 ne depende que de la profondeur Z par rapport au
Abstract: La theorie presentee permet d'obtenir une formulation explicite de l'influence des rugosites ainsi que des variations locales de constante dielectrique n2 (dues par exemple a une modification de composition ou de compacite) sur la reflexion rasante d'un faisceau de rayons X monochromatique, dans la mesure ou les rugosites relevent d'une distribution gaussienne et a condition que n2 ne depende que de la profondeur Z par rapport au plan moyen de la surface eclairee. L'analyse des verres silicates polis mecaniquement sur polissoir en poix, a l'aide de suspensions aqueuses d'oxydes divers, revele que la couche de polissage se compose en realite de deux zones bien distinctes. La premiere, tout a fait superficielle, l'epaisseur ne depassant pas quelques dizaines d'angstroms, presente une densite toujours inferieure a celle du coeur de l'echantillon et semble imputable au fluage plastique et a l'hydrolyse de la surface pendant le polissage. La seconde, sous-jacente, s'etend au contraire sur plusieurs centaines d'angstroms et met en jeu un processus soit de densification (silice pure, alumino-silicate) soit de lacunisation (verres a assez forte teneur en ions alcalins). Nous examinons egalement l'influence de la duree du polissage, du type d'oxyde utilise, et (ou) des traitements thermiques effectues apres polissage, sur les divers parametres qui caracterisent ces couches.
1,016 citations
TL;DR: In this paper, the half-widths of matrix relocation profiles were determined explicitly for ion-impurity knockon events (recoil implantation) as well as isotropic cascade mixing.
443 citations
TL;DR: In this article, a fractal geometry approach to spike formation is presented, based on an idealized collision cascade constructed from the inverse power potential V(r) √ r−1/m (0).
229 citations