• D Kanjilal

      Articles written in Bulletin of Materials Science

    • Temperature dependence of current—voltage characteristics of Au/n-GaAs epitaxial Schottky diode

      R Singh S K Arora Renu Tyagi S K Agarwal D Kanjilal

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      The influence of temperature on current-voltage (I-V) characteristics of Au/n-GaAs Schottky diode formed on n-GaAs epitaxial layer grown by metal organic chemical vapour deposition technique has been investigated. The dopant concentration in the epitaxial layer is 1 X 1016 cm-3. The change in various parameters of the diode like Schottky barrier height (SBH), ideality factor and reverse breakdown voltage as a function of temperature in the range 80–300 K is presented. The variation of apparent Schottky barrier height and ideality factor with temperature has been explained considering lateral inhomogeneities in the Schottky barrier height in nanometer scale lengths at the metal-semiconductor interface

    • Synthesis of copper nanoparticles in polycarbonate by ion implantation

      Annu Sharma Suman Bahniwal Sanjeev Aggarwal S Chopra D Kanjilal

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      Copper nanoparticles have been synthesized in polycarbonate by 75 KeV Cu ion implantation with various doses ranging from 6.4 × 1015 to 1.6 × 1017 ions/cm2 with a beam current density of 800 nA/cm2. The composites formed were structurally characterized using Ultraviolet-Visible (UV-Visible) absorption spectroscopy. The appearance of particle plasmon resonance peak, characteristic of copper nanoparticles at 603 nm in absorption spectra of polycarbonate implanted to a dose of 1.6 × 1017 ions/cm2, indicates towards the formation of copper nanoparticles in polycarbonate. Transmission electron microscopy further confirms the formation of copper nanoparticles having size ∼ 3.15 nm. The formation of copper nanoparticles in the layers carbonized by Cu implantation has been discussed. The synthesized copper-polycarbonate nanocomposite has been found to be more conducting than polycarbonate as ascertained using current–voltage characteristics.

    • Swift heavy ion irradiation induced modification of structure and surface morphology of BiFeO3 thin film

      B N Dash P Mallick P Dash R Biswal Jai Prakash A Tripathi D Kanjilal N C Mishra

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      BiFeO3 (BFO) thin films of thickness about 800 nm deposited on Si (100) substrates by sol–gel spin coating method were irradiated by 200 MeV Ag ions. Modification of structure and surface morphology of the films under irradiation was studied using glancing incidence X-ray diffraction (GIXRD) and atomic force microscope (AFM). Fluence dependence of GIXRD peak intensity indicated formation of 10 nm diameter cylindrical amorphous columns in crystalline BFO due to 200 MeV Ag ion irradiation. AFM analysis indicated that the pristine film consists of agglomerated grains with diffuse grain boundary. Irradiation led to reduced agglomeration of the grains with the formation of sharper grain boundaries. The rms roughness (𝜎rms) estimated from AFM analysis increased from 6.2 in pristine film to 12.7 nm when the film irradiated at a fluence of 1 × 1011 ions cm-2. Further irradiation led to decrease of 𝜎rms which finally saturated at a value of 7–8 nm at high ion fluences. The power spectral density analysis indicated that the evolution of surface morphology of the pristine film is governed by the combined effect of evaporation condensation and volume diffusion processes. Swift heavy ion irradiation seems to increase the dominance of volume diffusion in controlling surface morphology of the film at high ion fluences.

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