The pulsed laser deposition is a new technique for the growth of thin films,which has been attended generally by people recently The physical principle, unique characteristics and the proceeding of the study were introduced briefly In addation, the result of the PtSi nanometer thin film based on silicon prepared by the pulsed laser deposition was describedPULS

Pulsed laser deposition of thin films

Recent status of chemical bath deposited metal chalcogenide and metal oxide thin films

On the basis of dielectric measurements performed in a wide temperature range (173–373 K), a comprehensive analysis of the dielectric and electrical properties of magnetite nanoparticles electrical conduction mechanism of compressed spherical shaped Fe3O4 nanoparticles was proposed. The electrical conductivity of Fe3O4 nanoparticles was related to two different mechanisms (correlated barrier hopping and non-overlapping small polaron tunneling mechanisms); the transition between them was smooth. Additionally, role of grains and grain boundaries with charge carrier mobility and with observed hopping mechanism was described in detail. It has been confirmed that conductivity dispersion (as a function of frequencies) is closely related to both the long-range mobility (conduction mechanism associated with grain boundaries) and to the short-range mobility (conduction mechanism associated with grains). Calculated electron mobility increases with temperature, which is related to the decreasing value of hopping energy for the tunneling of small polarons. The opposite scenario was observed for the value of electron hopping energy.

Electrical conduction mechanism and dielectric properties of spherical shaped Fe3O4 nanoparticles synthesized by co-precipitation method

X-ray diffraction patterns of chemically deposited lead sulphide thin films have been recorded and X-ray line profile analysis studies have been carried out. The lattice parameter, crystallite size, average internal stress and microstrain in the film are calculated and correlated with molarities of the solutions. Both size and strain are found to contribute towards the broadening of X-ray diffraction line. The values of the crystallite size are found to be within the range from 22–33 nm and the values of strain to be within the range from 1·0 × 10−3–2·5 × 10−3.

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Structural characterization of lead sulfide thin films by means of X-ray line profile analysis

A TiO2 nanotubes array film with nanowires directly formed on top (denoted as TiO2 NTWs) was prepared by an anodization method (potentiostatic anodization growth). Bi2S3 QDs were sensitized on the CdS/TiO2 NTWs array by a simple successive ionic layer adsorption and reaction (S-SILAR). A short-circuit photocurrent density of 2.16 mA cm−2 was obtained under an illumination of AM 1.5 G. The data of the photoelectrochemical performance test show that Bi2S3/CdS co-modification can boost the photocurrent density of the bare TiO2 NTWs by up to 308%. The photocatalytic activity was tested by treating rhodamine B (RhB) and methyl orange (MO) solutions, which were degraded completely after 240 min and 210 min, respectively. The present study shows the Bi2S3/CdS/TiO2 NTWs array can be applied in photocatalytic devices, and the greatest advantages are low-cost, easy reuse and recyclability.

Simple synthesis method of Bi2S3/CdS quantum dots cosensitized TiO2 nanotubes array with enhanced photoelectrochemical and photocatalytic activity

In this paper, major reduction in sintering time,temperautre and significant improvement over final density of sitnered sample is reported for the microwave sintered nanocrystalline BiFeO3 (BFO) ceramic. Also, different sintering time and temperatures have been used to tailor the grain size and the final density of the resulting BFO ceramics synthesized from phase pure BFO nanoparticles (d ≈10 nm). Microwave sintering resulted in reducing the sintering time substantially (by 1h), and has resulted in submicron sized grains and high resistivity ∼1.8 GΩ-cm. The AC conductivity is seen to follow the Jonscher’s power law behavior, suggesting correlated barrier hopping (CBH) mechanism in the sample. The role of oxygen vacancies at high temperature, due to volatility of bismuth, in dielectric and conductivity behavior is also discussed. Further, the sample displayed dielectric anomaly near magnetic transition temperature (∼180 °C) indicating bearing of magnetic moments on the dielectric properties. Using Impeda...

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Impedance and AC conductivity study of nano crystalline, fine grained multiferroic bismuth ferrite (BiFeO3), synthesized by microwave sintering

Electrical and optical properties of Bi2S3 thin films deposited by successive ionic layer adsorption and reaction (SILAR) method

Mutliferroic and magnetoelectric gallium ferrite (GaFeO3) is plagued by substantial electrical leakage in polycrystalline form. Here, we report on understanding the conduction mechanism in gallium ferrite ceramic samples vis-a-vis processing conditions. The results show that oxygen annealed samples exhibit minimum electrical leakage as compared to air or nitrogen annealed samples suggesting the role of oxygen vacancies on electrical conduction. Detailed time and temperature dependent impedance spectroscopy analysis of the samples showed higher activation energy of conduction in oxygen annealed samples than in air or nitrogen annealed samples. The lower activation energies of 0.3-0.4 eV in nitrogen/air annealed samples were attributed to higher oxygen vacancy concentration while oxygen annealed samples with low oxygen vacancy concentration exhibited higher activation energy of ~0.50 eV (high frequency i.e. grain) and 0.98 eV (low frequency i.e. grain boundary), latter due to superior level of oxygenation at the grain boundaries. Further, X-ray photoelectron spectroscopy revealed that the oxygen vacancies are compensated by the valence fluctuation between Fe2+/Fe3+ ions whose extent is higher in air/nitrogen annealed samples than in oxygen annealed samples. The conduction mechanisms that could be active are most likely to be double ionization of oxygen vacancies and hopping between Fe2+ to Fe3+ states, latter especially in oxygen deficient samples.

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Effect of Annealing Atmosphere on Leakage and Dielectric Characteristics of Multiferroic Gallium Ferrite

Nanostructured thin films have attracted the attention of an increasing number of researchers from several disciplines during the last ten years, due to their outstanding electronic and optical properties and extensively useful applications in various optoelectronic devices. PbS thin films were deposited onto glass substrate by the method of chemical bath deposition (CBD) at 330 K temperature. The structure and surface morphology of the films were characterized by X-ray diffraction and scanning electron microscopy. The optical investigation showed that, depending on thickness films have direct allowed transitions in the range 1.88–2.28 eV. The decrease in dc dark resistivity with increase in grain size was also studied. The thermo-emf measurements show that deposited films were p-type in nature.

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A.S. Daryapurkar

Papers

Impedance and AC conductivity study of nano crystalline, fine grained multiferroic bismuth ferrite (BiFeO3), synthesized by microwave sintering

Electrical and optical properties of Bi2S3 thin films deposited by successive ionic layer adsorption and reaction (SILAR) method

Effect of Annealing Atmosphere on Leakage and Dielectric Characteristics of Multiferroic Gallium Ferrite

Thickness Dependent Structural, Electrical and Optical Properties of Chemically Deposited Nanopartical PbS Thin Films

Magnetoelectric properties of microwave sintered BiFeO3 and Bi0.90La0.10Fe0.95Mn0.05O3 nanoceramics