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In response of swift heavy ion (100 MeV I9+) irradiation, the irradiation‐induced disordering in nonstoichiometric pyrochlore composition (Nd1.8Zr2.2O7.1) was compared to that of stoichiometric composition Nd2Zr2O7. Both compositions were prepared through auto gel‐combustion followed by sintering under the identical conditions. Systematic analysis of the compositions before and after irradiation was performed with X‐ray diffraction (XRD), Raman spectroscopy, and plane‐view high‐resolution transmission electron microscopy (HRTEM) techniques. Irradiation caused pyrochlore to amorphous phase transformation was observed in both compositions except the slower rate of amorphization in Nd1.8Zr2.2O7.1. The amorphization was achieved as a consequence of isolated disordered track overlapping at higher ion fluence with the estimated track diameter 2.73 ± 0.05 and 3.46 ± 0.30 nm for Nd1.8Zr2.2O7.1 and Nd2Zr2O7, respectively, employing the framework of single‐ion impact model to XRD results. HRTEM micrographs also revealed the less prevalence of irradiation‐induced amorphization in Nd1.8Zr2.2O7.1 with the observed irradiation‐induced modified track region composed of defect‐rich pyrochlore structure, anion‐deficient fluorite structure, and amorphous domains; with the diameter of 3.0 ± 1.0 nm and 5.0 ± 1.0 nm in Nd1.8Zr2.2O7.1 and Nd2Zr2O7, respectively. The preexisting anion‐deficient fluorite structure in Nd1.8Zr2.2O7.1 helps in its epitaxial growth as recovered structure from melted ion track during irradiation‐induced rapid cooling. [ABSTRACT FROM AUTHOR]

The radiation-resistant response of BaTiO3 in the tetragonal and rhombohedral phases on exposure to 100 MeV Ag7+ ion irradiation was investigated by in situ X-ray diffraction (XRD) at room temperature (300 K) and low temperature (25 K), respectively. This study revealed that the BaTiO3 in rhombohedral phase retained crystallinity up to an ion fluence of 1×1014 ions/cm2, whereas tetragonal phase amorphized at much lower fluence viz. 1×1013 ions/cm2. The in situ XRD along with Raman spectroscopy studies revealed that BaTiO3 in rhombohedral phase is more radiation resistant than that of tetragonal phase. The density functional theory ( DFT) calculations confirmed higher bond strength of rhombohedral phase as compared to tetragonal phase, which supported the experimental result of higher radiation stability of rhombohedral phase. The theoretical predictions on high-temperature phase will be of relevance to the nuclear waste applications. [ABSTRACT FROM AUTHOR]

In order to simulate radiation damages in tungsten, potential plasma facing materials in future fusion reactors, surrogate approach of heavy ion irradiation on polycrystalline tungsten is employed. Tungsten specimen is irradiated with gold heavy ions of energy 120 MeV at different fluences. Positron annihilation lifetime measurements are carried out on pristine and ion beam irradiated tungsten specimens. The variation in positron annihilation lifetime in ion irradiated specimens confirms evolution of vacancy clusters under heavy ion irradiation. The pristine and irradiated tungsten specimens have also been characterized for their microstructural, structural, electrical, thermal, and mechanical properties. X-ray diffractograms of irradiated tungsten specimens show structural integrity of polycrystalline tungsten even after irradiation. Nevertheless, the increase in microstrain, electrical resistivity and microhardness on irradiation indicates creation of lattice damages inside polycrystalline tungsten specimen. On the other hand, the thermal diffusivity has not change much on heavy ion irradiation. The induction of damages in metallic tungsten is mainly attributed to high electronic energy loss, which is 40 keV/nm in present case as obtained from SRIM program. Although, concomitant effect of nuclear losses on damage creation cannot be ignored. It is believed that the energy received by the electronic system is being transferred to the atomic system by electron-phonon coupling. Eventually, elastic nuclear collisions and the transfer of energy from electronic to atomic system via inelastic collision is leading to significant defect generation in tungsten lattice. [ABSTRACT FROM AUTHOR]

Research progress in the field of synthesis of graphene-like nanosheets has been expeditiously growing in the recent years because of their incredible properties in various fields offered by these two-dimensional nanostructures. Nano order thick graphitic flakes, one of the forms of graphene, can be used for many applications such as conductive inks, supercapacitors, nanofluids, gas sensing, etc. Synthesis of graphene flakes definitely the way to reach bulk quantity production. Preparation of stack layer graphene-like nanosheets from industrial waste carbon flake is important for scalable production at a low cost and societal uses. Our novel work surmised the fabrication of Nano order thick graphitic flakes from industrial waste using the modified hummer's method. The basic morphological characteristics have been examined by X Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Gas sensor was prepared by depositing a thin film on a figure-type interdicted electrode epoxy substrate. The sensing behavior was detected by monitoring the change in resistance after hydrogen gas exposure using a computer control indigenously developed hydrogen gas sensing unit. • This work presents novel synthesis of Nano order thick graphene-like nanosheets from industrial waste using hummer's method. • The qualitative and quantitative analysis of synthesize nanosheets have done by characterized physicochemical properties. • The synthesize nanosheets based chemiresistor type gas sensor was prepared and tested for hydrogen gas. • The sensor shows the faster response and higher sensitivity over a long period toward hydrogen gas at room temperature. [ABSTRACT FROM AUTHOR]

Highlights: [•] Effect of volume fractions on change in the size of embedded silver nanoparticles. [•] Surface plasmon resonance study to understand the dipolar interactions. [•] Study provides data for the development of non-equilibrium thermodynamics. [ABSTRACT FROM AUTHOR]

Abstract: Our long term objective is to study the swift heavy ion (SHI) irradiation effect on photoanode of dye-sensitized solar cell (DSSC) with the aim to investigate the stability of DSSC component in space irradiations and possibility of improvement in efficiency of DSSC due to ion induced effects in oxide layer. The DSSC photoanode consists of three layers viz; transparent conducting oxide (TCO), porous oxide with wide band gap and monolayer of dye molecule on top of corning glass substrate respectively. In the present study, procured radio frequency (RF) sputtered indium tin oxide (ITO) film on corning glass substrate were irradiated by SHI using 110MeV Ni8+ ions at different fluences ranging from 3.0×1011 ion/cm2 to 1.0×1014 ion/cm2. After irradiation significant changes have been observed in the structural, optical and electrical properties using X-ray diffraction (XRD), UV–Vis and Four Probe measurements, respectively. Overall there is 13% increase in optical transmittance which is favorable and moderate increase in sheet resistance from 8Ω/□ to 18Ω/□ which is still within acceptable limits for DSSC applications. [ABSTRACT FROM AUTHOR]