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The energy and power density of lithium-ion batteries (LIBs) can be effectively improved by designing flexible free-standing electrodes. Here, a flexible film composed of Fe3O4 nanoparticles (NPs) embedded in N-doped carbon nanofibers (Fe3O4/NCNFs) was prepared through electrospinning and subsequent annealing process. The Fe3O4/NCNFs film can be directly used as anode materials for LIBs without conductive additive, current collector, and binder. Electrochemical measurement results indicate that the Fe3O4/NCNFs electrode exhibits excellent cycling stability and retains the capacity of 522 mAh g−1 after 200 cycles at 0.1 A g−1. Furthermore, the Fe3O4/NCNFs electrode also shows good rate performance and still obtains a specific capacity of 407 mAh g−1 even at 5 A g−1. The superior electrochemical performance should be attributed to the flexible self-standing characteristic of the electrode and the synergistic effects between 3D conductive NCNFs and Fe3O4 NPs.

Kapok fibres were used as micro-tube biotemplate and bio-carbon source to synthesise Fe 3 O 4 /C composites, which were then utilised as anode materials. Fe 3 O 4 nanoparticles were grown uniformly onto the external surface and internal channel of kapok carbon fibres. The flexibility, high specific surface area and electronic conduction of kapok fibres can buffer the volume expansion as well as inhibit the aggregation of Fe 3 O 4 nanoparticles. Thus, the electrical integrity and structural of the Fe 3 O 4 /C composites electrode during lithiation/delithiation processes. The Fe 3 O 4 /C composites electrode delivers a high reversible capacity of 596 mA h g −1 after 100 cycles and an ultra-high coulombic efficiency approaching 100%. The high electrochemical performance of the Fe 3 O 4 /C composites can be caused by the synergistic effect of the Fe 3 O 4 nanoparticles and the structure of kapok carbon fibres.

High performance nitrogen-doped carbon (NC) materials decorated with MnO hybrid (MnO@NC) composites with a nanopeapod appearance were synthesized by with a simple hydrothermal method and insuit-polymeric route. As an anode material for lithium ion batteries (LIBs), the nanopeapod structure of MnO@NC composites with internal void spaces exhibits good rate capability, high conductivity and excellent cycling stability. After 200 cycles, the nanopeapod composites yield a specific capacity of 775.4 mAh g−1 at 100 mA g−1 and a high-rate capacity of 559.7 mAh g−1 at 1000 mA g−1. The proposed synthesis of nanopeapod structure composites with an internal room is an efficient design with excellent electrode materials for rechargeable LIBs.

A planar optical waveguide has been formed in a LiB 3 O 5 crystal using 6.0 MeV Cu + -ions with a dose of 1 × 10 15 ions/cm 2 at room temperature. Possible propagating modes were measured at a wavelength of 633 nm using the prism-coupling method. The refractive index profiles of the waveguide were reconstructed by an effective refractive index method and the beam propagation method was used to investigate the properties of the propagation modes in the formed waveguide. The results suggest that the fundamental TE 0 and TM 0 modes may be well-confined and propagate a longer distance inside the waveguide. The implantation process was also simulated using the transport of ions in matter code (TRIM), which indicates that the nuclear energy deposition may be the main factor for the refractive index change.

We reported for what is to be believed the first time a double optical waveguide in a Cu-doped potassium sodium strontium barium niobate (KNSBN) crystal formed by double boron ion implantation. The energy and dose of B + and B 3+ ions were (3+6) MeV and (2+2)×10 14 ions/cm 2 , respectively. The refractive index profile of the waveguide showed a double-barrier confined shape, which suggested the formation of a two-layer waveguide structure. The two waveguide layers were with thickness of 2.6 and 2 μm, respectively, which was in a good agreement with the parameters obtained from transport and range of ions in matter 98 (TRIM) code simulation. The nuclear energy loss distribution of the MeV B ions implanted into this crystal had a similar shape to that of the waveguide index profile, which means an inherent relationship between the waveguide formation and the energetic energy deposition.

Planar optical waveguides were formed in Ce:SBN and Cu:KNSBN crystals, respectively, by means of 6.0 MeV B3+ ion implantation at a dose of 2×1014 ions/cm2 at room temperatures. The prism coupling method was performed to characterize the dark-mode property of the waveguides. The reconstructed refractive index profiles in the waveguides were found to be typical barrier-type distributions. Transport and range of ions in matter (TRIM 98) code was used to simulate the process of the implantations. The shapes of nuclear energy loss distribution of the B3+ implantation were similar to those of the waveguide refractive index profiles, which means an inherent relationship between the waveguide formation and the energetic energy deposition.

The 2.8 MeV Ni+ ion-implanted planar optical waveguide in Nd:YVO4 crystal is reported. The prism coupling method is used to measure the dark modes of the Nd:YVO4 waveguide. It is found that the effective refractive indices of all the extraordinary modes are lower than that of the substrate (ne), while the effective indices of the first three ordinary modes have a positive change compared with that of the substrate (no). Both ne and no profiles in the waveguide are reconstructed by reflectivity calculation method (RCM).

The irradiation damages produced in silicon crystal by 0.7 and 0.4 MeV per atom Sin (n=1–3) were measured. The results of the measurement showed that the relationship between the defect concentrations and the cluster sizes is non-linear; and that the ratio of the defect concentration induced by clusters to that by single atoms increases with the decrease of the energy per atom for given-sized clusters. The experimental results can be well explained by the cooperation of the electronic and nuclear stopping processes.

The data are presented on the waveguides formation in the Nd 3þ -doped silicate glass and Er 3þ /Yb 3þ co-doped phosphate glass by the implantations of He þ or Si þ ions, respectively. The prism-coupling method is used to measure the effective refractive indices of the waveguide dark modes. The refractive index profiles of the waveguides are reconstructed by using the reflectivity calculation method (RCM) and a comparison of such profiles among the different waveguides has been made. The reasons for the formation of the present waveguides are analyzed in a primary way. # 2002 Elsevier Science B.V. All rights reserved.

BiB3O6 and Nd:YVO4 planar waveguides were fabricated by MeV Si+ (with a dose of 1×1014 ions/cm2) and Cu+ (with a dose of 1×1015 ions/cm2) ion implantation, respectively. Prism coupling method was used to observe the dark modes of the BiB3O6 and Nd:YVO4 waveguides. Reflectivity calculation method (RCM) was applied to simulate the refractive index profiles in the guiding layer. Obvious positive refractive index changes in the surface layer were induced by the ion implantation, which confined the region beneath the surface for many microns to be waveguide structures.

The first MeV phosphor ion implanted planar optical waveguide in KTiOPO4 (KTP) is reported. The modes in the KTP waveguide were measured by dark mode coupling method using a model 2010 prism coupler. The refractive index profile was analyzed by reflectivity calculation method (RCM) at room temperature, after treatment at 200°C for 30 min (in air) and 77 K for 150 min (in liquid nitrogen), respectively.

The Si samples containing the B marker layer or pre-buried dislocation loop layer were implanted with 140 keV 1×1015 Ge/cm2 and 30 keV 5×1013–1×1015 B/cm2, respectively. The interaction mechanism between the damage distributions arising from different implant stages was investigated by means of monitoring the interstitial fluxes during anneal by transient enhancement diffusion (TED) of the B marker and the evolution of the end of range (EOR) dislocation loop `detectors'. The results demonstrate further that the distribution where secondary defects formed first will getter the Si interstitials from the other damage profile and affect the formation of secondary defect there. The experiment shows the formation of the B–Si interstitial clusters affected the diffusion of B impurity atoms and Si self-interstitials. The results might offer a basic knowledge for designing the ion beam defect engineering (IBDE).

The stopping powers for 0.32–0.43 MeV/A 16O ions in Al, Cu and Ag foils have been measured with the elastic recoil detection (ERD) method. The results are compared with the calculated values of SRIM2000 and previous experimental data.