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We created a unique sodium ion battery (NIB, SIB) cathode based on selenium in cellulose-derived carbon nanosheets (CCNs), termed Se-CCN. The elastically compliant two-dimensional CCN host incorporates a high mass loading of amorphous Se (53 wt%), which is primarily impregnated into 1 cm3 g−1 nanopores. The results in facile sodiation kinetics due to short solid-state diffusion distances and a large charge transfer area of the nanosheets were established. The architecture also leads to an intrinsic resistance to polyselenide shuttle and to disintegration/coarsening. As a Na half-cell, the Se-CCN cathode delivers a reversible capacity of 613 mA h g−1 with 88% retention over 500 cycles. The exceptional stability is achieved by using a standard electrolyte (1 M NaClO4 EC-DMC) without secondary additives or high salt concentrations. The rate capability is also superb, achieving 300 mA h g−1 at 10C. Compared to recent state-of-the-art literature, the Se-CCN is the most cyclically stable and offers the highest rate performance. As a Se–Na battery, the system achieves 992 W h kg−1 at 68 W kg−1 and 384 W h kg−1 at 10144 W kg−1 (by active mass in a cathode). We are the first to fabricate and test a Se-based full NIB, which is based on Se-CCN coupled to a Na intercalating pseudographitic carbon (PGC) anode. It is demonstrated that the PGC anode increases its structural order in addition to dilating as a result of Na intercalation at voltages below 0.2 V vs. Na/Na+. The {110} Na reflections are distinctly absent from the XRD patterns of PGC sodiated down to 0.001 V, indicating that the Na metal pore filling is not significant for pseudographitic carbons. The battery delivers highly promising Ragone chart characteristics, for example yielding 203 and 50 W h kg−1 at 70 and 14000 W kg−1 (via total material mass in the anode and cathode).

Nearly monodispersed 1.6 nm Ir, 2.3 nm Pd nanoparticles, 2.7 nm Pd(core)–Ir(shell) and 2.2 nm Pd–Ir alloys with mixed surface atoms were synthesised in the presence of polyvinylpyrrolidone (PVP) and studied in the atmospheric ring opening of indan. The nanoparticles and supported catalysts were characterised by UV–vis spectroscopy, TGA, TEM, EDX, TPR, XPS, ISS and XANES. The nanoparticle size and structure control allowed insights into the bimetallic catalyst functioning. As soon as two contiguous surface Ir atoms exist on the nanoparticle surface, they display the same catalytic properties, most likely through the dicarbene ring-opening mechanism. Palladium serves only as a dispersing agent in Pd(core)–Ir(shell) structures providing 100% Ir dispersion, or as an inert surface diluting metal in Pd–Ir formulations with mixed nanoparticle surface. The Pd–Ir core–shell structure allows maximum selective ring-opening yield, which is 19% higher than that for the industrial Pt–Ir catalyst.

Low-power pulsed-laser annealing was applied to Zn+-implanted InP samples. In order to avoid surface oxidation during the treatment, the laser irradiation was carried out in inert ambient of nitrogen at different pressures. The analytical techniques used include Rutherford backscattering spectroscopy, reflection high energy electron diffraction, and electrical measurements. The highest carrier activation, about 80%, was achieved at the same laser power density (6.5 MW/cm2) at which the best crystal recovery was obtained.

A two-dimensional classical dynamics model for calculating the reflection coefficient of keV-ion beams backscattered from a crystal surface at glancing incidence is presented. The target is considered as consisting of one or two layers of atomic strings. A string potential of cylindrical symmetry was constructed by using the well-known iuniversali pair potential or the Molire interatomic potential. The critical transverse energy needed for a 100% reflection of light ions from the surface is assessed for the most open (11 _ 0) direction of Cu(111), Ni(111), and Al(111) crystal surfaces. The distribution of the backscattered ions on the azimuthal scattering angle exhibits the multimode structure related to the zig-zag trajectories in surface semichannels. The energy spectra are compared to the experimental data. The simulations show that the reflection coefficient is substantially dependent on the interatomic potential used but is not much affected by the model adopted for description of the inelastic losses. The inelastic-interaction model affects mostly the energy peak position, so that an estimate based on OennRobinson empirical formulae compares better with the experimental data than the original Firsov model. Resume : Nous prOsentons un modle de dynamique classique en 2-D pour calculer le

Wafers of (100) GaAs have been implanted with 140 keV Zn+ ions at off-channeling direction up to a fluence of 1×1014 cm−2. The target temperature was kept at 110±10°C. The defect clusters and the damage depth distributions were investigated by planar and cross-sectional high-resolution transmission electron microscopy (HRTEM and XHRTEM) and were modelled by a MAR-LOWE-based computer code. The experimental mean depth of the damage profile located at about 85 nm exceeds the calculated deposited energy and vacancy distributions by more than 50%. The correlation between the deposited energy density within the cascade and the inner structure of the observed defect clusters is discussed.

GaAs 〈100〉 wafers were implanted and later annealed by using three different techniques: furnace thermal annealing (FTA), flash lamp (RTA) and low-power laser annealing (LPLA). The resulting modifications of the structure were studied by RHEED. The RHEED pattern analysis indicates that: (a) A well annealed structure is observed after thermal treatment in furnace at 850 °C for 30 min; (b) the particular RTA employed leads to some texturing, but is not sufficient to provide good structural effects; (c) best annealing under our conditions is obtained by the LPLA technique, especially for low ion doses (less than 1013 cm−2); (d) variable-glancing-angle RHEED is an effective and convenient method to investigate the ion induced disorder in crystals at small depths.

Low‐power annealing by a pulsed laser is used to recover the structure of low‐dose implanted (100) GaAs crystals. Reflection high‐energy electron diffraction with variable glancing incidence is employed to detect the structural changes at different depths in the specimens. The depth dependence of the damage is studied in more detail by Rutherford backscattering analysis. The annealing results depend on the irradiation conditions. A laser energy window below the melting threshold is found within which the structure can be restored to about as high degree of crystallinity as the virgin one, without any visible surface damage. A simple theoretical estimate shows that the temperature rise of the material is far below the melting threshold. This rise is too short in time to cause substantial dopant diffusion; however, it can enhance well the point‐defect mobility.

(1 0 0)-oriented silicon substrates were implanted with 50 keV Te + or Pb + ions at room temperature with doses varied in the range 1×10 15 to 1×10 18 cm −2 . Formation of ion beam-assisted Te and Pb nanocrystals in the layer amorphised by the implantation has been established. The accumulation of impurities, sputtering and formation of high-dose implantation profile was modelled by a dynamic computer simulation code. The calculated concentration profiles at various ion fluences were compared with the measured RBS profiles and the depth distribution of ion beam-induced nanoclusters obtained by cross-sectional transmission electron microscopy (XTEM), in an attempt to clarify the role of these effects in the formation of precipitates at high-dose irradiation conditions.

The effects of the ambient atmosphere in the annealing chamber on the electrical and structural characteristics of Zn-implanted III-V compound semiconductors, processed by low-power pulsed-laser annealing are presented. The samples were analyzed using several complementary experimental techniques: Reflection high-energy electron diffraction, Rutherford backscattering spectroscopy, Raman spectroscopy, secondary ion mass spectroscopy, and electrical measurements. During the laser beam irradiation in the presence of gas inlet into the annealing chamber the ambient gas atoms diffused well into the target changing the stoichiometry and the electrical parameters. Redistribution of the implanted impurity was also observed. By varying the type of gas used and its pressure, it was possible to achieve electrical activation of up to 80%. It seems all structure and electrical parameters achieve their best values at the same ambient atmosphere and density of the deposited laser power P, e.g., 1.5 atm of ${\mathrm{N}}_{2}$ and $P=6.5 {\mathrm{M}\mathrm{W}/\mathrm{c}\mathrm{m}}^{2}$ for InP.

Data on the effects of 140 keV Zn+ implanation of (100)GaAs and the consequent low-power pulsed laser annealing (LPPLA) on the composition of the surface layers are presented. The implantation does was 1014 cm −2 and the sample temperature was kept at 110 ± 10°C. THE LPPLA was carried out by 10–30 pulses of a Q-switched ruby laser (λ = 694.3 nm, τ = 25 ns and P0 = 4–6 MW cm−2) equipped with a spatial homogenizer. The crystal surface was studied by XPS analysis combined with depth profiling with the use of 1 keV Ar+. The results presented include the depth redistribution of oxygen and the As/Ga ratio as well as the oxide thickness for (a) virgin, (b) as-implanted and (c) implanted and then annealed samples.

〈100〉GaAs crystals were implanted with 140 keV Zn ions at random incidence and a dose of 1014 cm−2. Annealing by a low-power pulsed laser was used to recover the radiation damage. The samples were analysed by RHEED and RBS techniques. The effect of the annealing on the recovery of structure defects in GaAs is reported.

The scattering of Ar, Ne, and He ions from the Cu {100} face has been investigated by a digital computer technique; only binary elastic collisions of ions with the lattice atoms have been considered; the angular and energy distribution at various directions of incidence are discussed. The scattering by surface atomic chains and its contribution to the general picture of ion reflection were also studied.

Reflection high-energy electron diffraction (RHEED) and X-ray photoelectron spectroscopy (XPS) were used to demonstrate the effects of Zn + -ion implantation and subsequent low-power pulsed laser annealing (LPPLA) on the crystallinity and the P/In ratio near the surface of InP. The influence of ion-beam effects during depth profiling by a 1 to 5 keV Ar beam on the composition of surface layers is discussed in terms of XPS data compared to computer simulation results using a dynamic model based on TRIM. Relative enrichment in P of the topmost surface layer of virgin samples along with the P deficiency below the surface is confirmed by both XPS and computer simulation data, the effect being more pronounced for higher energies of the depth-profiling Ar + beam. Severe C and O contamination is found on the ion-implanted InP surface exposed to air. The P/In ratios at and below the surface (to about 10 nm depth) differ from that for the virgin sample. Both RHEED and XPS demonstrate the efficiency of laser pulses at a power density of 6 MW/cm 2 in recovering the structure and stoichiometry of ion-implanted crystals of InP.