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In this present work the characteristics of Chromium nitride (CrN) thin films on Silicon substrate were investigated as function of Nitrogen gas flow rate. Chromium nitride (CrN) thin films were fabricated on single crystal silicon substrates by using the reactive ion beam sputtering at room temperature. Effect of N2 gas flow on microstructure, surface roughness and density were investigated by GIXRR and GIXRD by depositing [CrN]x4 films at various N2 gas flow from 1sccm to 4sccm while keeping the Ar flow constant at 2.5 sccm. The effects of N2 gas flows on the deposition rate showed that the deposition rate decreases with the increase of nitrogen gas flow. X-ray study shows that the surface roughness and density of the CrN films increases with the increase of N2 gas flows. It is suggested that the ion and particles bombardment at low gas pressures cause a smoother surface.

Weight loss studies have been performed to determine the corrosion resistance of amorphous Zr60 Nb 2 Al 10 Ni 8Cu20 and Zr59 Nb 3 Al 10 Ni 8Cu20 alloys in aqueous HNO3 media at boiling temperature. The FESEM micrographs has been obtained to know the surface morphology of specimens after immersion in 11.5M boiling aqueous HNO3 media. Zr59 Nb 3 Al 10 Ni 8Cu20 alloy shows better corrosion resistance in nitric acid media than Zr60 Nb 2 Al 10 Ni 8Cu20 alloy.

W/Si multilayers four samples have been deposited on silicon substrate using ion beam sputtering system. Thickness of tungsten (W) varies from around 10 A to 40 A while the silicon (Si) thickness remains constant at around 30 A in multilayers [W-Si]x4. The samples have been characterized by grazing incidence X-ray diffraction (GIXRD) and X-ray reflectivity technique (XRR). GIXRD study shows the crystalline behaviour of W/Si multilayer by varying W thickness and it is found that above 20 A the W film transform from amorphous to crystalline phase and X-ray reflectivity data shows that the roughnesses of W increases on increasing the W thicknesses in W/Si multilayers.

Thin film of compound material ZrC was deposited on Si (100) wafer using ion beam sputtering method. The deposition was carried out at room temperature and at base pressure of 3×10−5 Pa. X-ray photoelectron spectroscopy (XPS) measurements were performed for determining the surface chemical compositions. Grazing incidence x-ray reflectivity (GIXRR) measurements were performed to study the film thickness, roughness and density. From GIXRR curve roughness value of the film was found less than 1 nm indicating smooth surface morphology. Films density was found 6.51 g/cm3, which is close to bulk density. Atomic force microscopy (AFM) measurements were performed to check the surface morphology. AFM investigation showed that the film surface is smooth, which corroborate the GIXRR data.Figure 2 of the original article PDF file, as supplied to AIP Publishing, contained a PDF processing error. This article was updated on 12 May 2014 to correct that error.

NbC films were prepared using Ion beam sputtering system at various discharges current from 0.4 amps to 1.2 amps at room temperature. Effect of temperature on NbC films were also studied by depositing NbC films at various temperatures from room temperature to 200,300,400 and 600°C. X-ray reflectivity (XRR) study shows that surface roughness of the film decreases with decrease in discharge current. The optimum lowest roughness 3.2A having density 92% of bulk was achieved at discharge current 0.6 amps at 3.0 cm3/min Ar gas flow. X-ray study also shows that film roughness decreases with increase in temperature of the film and after a certain temperature it increases with increase in temperature. The lowest surface roughness 2.1A was achieved at 300°C with density 83% of bulk NbC at constant discharge current 0.6 amps.

We demonstrate that room temperature ferromagnetism (RTFM) can be induced in pristine In2O3 bulk powder through hydrogenation. The oxygen vacancies (Vo) accompanied by defect complexes In2+–Vo are produced in hydrogenated In2O3. However, the ferromagnetic ordering disappears upon removing these Vo’s and defect complex upon re-heating the hydrogenated sample in air. The hydrogenation induced In3d–O2p hybridization, the defect complexes In2+–Vo and the Vo’s compositely contribute to observed ferromagnetic ordering.

Nanocystalline Cu0.2Ni0.8Fe2O4 of average particle size 3 nm was synthesized through chemical coprecipitation method followed by annealing at various temperatures. The formation of cubic spinel structure in single phase and the crystallite growth was confirmed using XRD. The dielectric behavior as a function of frequency in the range 75 kHz to 10 MHz was studied at room temperature. Both dielectric constant (e′) and the loss factor (tanδ) decreases with frequency for all samples. This decrease in the values could be explained on the basis of available ferrous, i.e. Fe2+, ions at octahedral sites such that beyond a certain frequency of applied electric field the electronic exchange between the ferrous and ferric ions i.e. Fe2+↔Fe3+ cannot follow the applied alternating electric field.

Series of nanocrystalline Cu1-xZnxFe2O4 (x=0.2, 0.4, 0.6 and 0.8) spinel ferrites were synthesized using advanced sol-gel technique. The XRD measurements confirm the formation of cubic spinel structure in single phase for the entire sample. The average particle sizes of 14-18 nm with lattice parameter ranges from 8.38A to 8.52A were estimated. Cation distribution over the two sites of nanocrystalline Cu1-xZnxFe2O4 series, estimated from X-ray diffraction measurements is reported. The lattice parameter ‘a’ is found to be increased with increase in Zn concentration, which is attributed to the larger ionic radius of Zn compared to that of Cu.

Polycrystalline YBa2(Cu1−XZnX)3O7−δ samples (x=0.0 to 0.06) were studied using XRD, titration, resistivity, magnetization and XPS measurements. The O2 stoichiometry (δ) is found to change on Zn substitution which affects the normal state resistivity of the system as well as the superconducting transition temperature (TC). Interestingly, the non-magnetic Zn ions also induce local magnetic moment as confirmed from the M-H curves. It is concluded that Zn doping induced change in O2 stoichiometry and the magnetic pair breaking cause a rapid suppression in superconductivity.

We have investigated correlation between magnetization and electronic structure in Zn0.98Mn0.02O nano-rods. Rietveld analysis of XRD patterns confirms that Mn ions incorporate at the Zn2+ sites. SQUID measurements confirm that Mn doping induces room temperature ferromagnetism (RTFM) in nano-rods and the induced magnetization is an order of magnitude higher than that in the bulk Zn0.98Mn0.02O. The XPS results show that Mn ions are in mixed valent state. Our findings show that bivalence of Mn ions and the oxygen vacancies are responsible for the observed RTFM.

Cobalt (Co) films were prepared, using ion beam sputtering technique. Films were prepared by varying beam voltage from 700 to 1100 V at room temperature. The influence of ion beam energy on the density, surface roughness and thickness uniformity of Co film was investigated. X-ray reflectivity study shows that surface roughness of film decreases with increasing beam energy and lowest surface roughness of 1.3 A was achieved for 1000 V beam voltage at 4 cm3/min Ar gas flow. The density of the film was 93% of bulk density of Co. These ultra low roughness films are very promising for studying the magnetic properties of Co films.

Series of nanocrystalline Cu1−xZnxFe2O4 (x = 0.2, 0.4, 0.6 and 0.8) spinel ferrites have been synthesized using advanced sol‐gel method. The XRD measurements confirm the formation of cubic spinel structure in single phase for all the samples and the average particle sizes are 14–18 nm. In this paper the dc magnetization study for one sample Cu0.4Zn0.6Fe2O4 is reported. The nanocrystalline sample is superparamagnetic above the blocking temperature of 180 K. The reduction in saturation magnetization is attributed to disordered magnetic moments at surface around the core of nanoparticles.

Dielectric behavior of nanosized ZnCrxFe2−xO4 particles with x = 0.2, 0.4, 0.6 and 0.8, synthesized using sol‐gel method have been studied. The XRD patterns confirm formation of single phase cubic spinel structure of the specimens. The dielectric behavior of all the samples has been studied at 300 K as a function of frequency in the range 75 kHz to 10 MHz. Both the real value of dielectric constant (e) and the dielectric loss factor (tanδ) decreases with frequency respectively for all the samples. This decrease in the values could be explained on the basis of available ferrous, i.e. Fe2+, ions on octahedral sites such that beyond a certain frequency of applied electric field the electronic exchange between the ferrous and ferric ions i.e. Fe2+↔Fe3+ cannot follow the applied alternating electric field. Also, a gradual reduction in both e and tanδ observed as Cr concentration increases.

The influence of buffer layer on interface roughness has been investigated. With Si buffer layer, NbC/Si multilayer mirrors show 28% increase of reflectivity at 1st Bragg peak for 1.54A0. Reduction in physical and chemical roughness in the multilayer with buffer layer was calculated by fitting both specular and diffused scattering data.

This paper reports the synthesis of bulk sized Zn0.8Mn0.2Fe2O4 particles by solid state method followed by high energy ball milling at different times yielding nannocrystalline samples of different sizes. The dielectric behavior of the samples has been studied at 300 K as a function of frequency in the range 75 kHz to 10 MHz. Both the real value of dielectric constant (e′) and the dielectric loss factor (tanδ) decreases with frequency respectively for the three samples. Also the reduction in the value of e′ and tan δ for the ball milled samples is attributed to the least possibility of occurrence of Fe2+ ions at the octahedral site as size reduces.

Particle size has significant effect on the magnetic properties of nano‐particles. Nano‐particles of Cu‐Ni ferrite have been synthesized by the co‐precipitation method. Different particle sizes (3nm‐9 nm) were obtained by annealing the prepared samples at various temperatures. The specimens characterized using XRD confirmed the formation of cubic spinel structure. The samples show typical superparamagnetic behaviour above blocking temperature. The particle size increases with increasing the annealing temperature. The saturation magnetization & blocking temperature increases with particle size which is characteristic of superparamagnetism. The hysteresis curves show reduction in saturation magnetization in the case of nanoparticles as compared to their bulk counterpart, which have been explained on the basis that the magnetic moments in the surface layers of a nanoparticle are in a state of frozen disorder. However the saturation magnetization increases with particle size, which is the characteristic property of single domain superparamagnetic particles.

Conducting polymers have been widely investigated for both academic and industrial purposes over three decades. Thin film of polyaniline(PANI) upon ITO coated glass was electrodeposited using direct power supply method. In this method stainless steel electrode was used as cathode and ITO coated glass as anode. 0.1 M aniline monomer and 0.5 M H2SO4 solution in distilled water was used as electrolyte. The electric current in the electrolite was supplied at fixed voltage 1.5 volt upto the required time to obtained the desired thickness of the polymer film. An attempt has been made to estimate various electronic perameters such as barrier height through I/V measurements of the polyaniline film upon ITO coated glass. The surface morphology of the film material was studied by scanning electron microscopy. The film material was also characterised by X‐Ray Difractometer & FTIR The value of potential barrier O/b &constant factor s was obtained using Schottky equations. Bandgap calculations were carried out by usin...

In this research, resonant infrared matrix‐assisted pulsed laser evaporation (RIR‐MAPLE) has been used to deposit different classes of inorganic nanoparticles, including bare, un‐encapsulated ZnO and Au nanoparticles, as well as ligand‐encapsulated CdSe colloidal quantum dots (CQDs). RIR‐MAPLE has been used for thin‐film deposition of different organic/inorganic hybrid nanocomposites using some of these inorganic nanoparticles, including CdSe CQD‐poly[2‐methoxy‐5‐(2’‐ethylhexyloxy)‐1,4‐(1‐cyanovinylene)phenylene] (MEH‐CN‐PPV) nanocomposites and Au nanoparticle‐poly(methyl methacrylate) (PMMA) nanocomposites. The unique contribution of this research is that a technique is demonstrated for the deposition of organic‐based thin‐films requiring solvents with bond energies that do not have to be resonant with the laser energy. By creating an emulsion of solvent and ice in the target, RIR‐MAPLE using a 2.94 μm laser can deposit most material systems because the hydroxyl bonds in the ice component of the emulsion matrix are strongly resonant with the 2.94 μm laser. In this way, the types of materials that can be deposited using RIR‐MAPLE has been significantly expanded. Furthermore, materials with different solvent bond energies can be co‐deposited without concern for material degradation and without the need to specifically tune the laser energy to each material solvent bond energy, thereby facilitating the realization of organic/inorganic hybrid nanocomposite thin‐films. In addition to the structural characterization of the inorganic nanoparticle and hybrid nanocomposite thin‐films deposited using this RIR‐MAPLE technique, optical characterization is presented to demonstrate the potential of such films for optoelectronic device applications.

The polarization measurement through elastic (p,C) reaction plays a crucial role in the polarized proton beam operation of Relativistic Heavy Ion collider at Brookhaven National Laboratory. As well as measuring the polarization, the unknown analyzing power AN of elastic (p,C) is determined as well in combination with the absolute polarization meausement by a H‐jet polarimeter. The systematic uncertainty of the Run05 measurements are discussed as well as introducing the experimental apparatus of the polarimeter system.

Precise and absolute beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy of $\Delta P_{beam}/P_{beam} < 5%$. The absolute polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detectors and was installed in the RHIC-ring in 2004. This system features \textit{proton-proton} elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power $A_N$ of this process has allowed us to achieve $\Delta P_{beam}/P_{beam} =4.2%$ in 2005 for the first long spin-physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004-2005 are described. Physics topics of $A_N$ in the CNI region (four-momentum transfer squared $0.001 < -t < 0.032 ~ ({\rm GeV}/c)^2$) are also discussed. We point out the current issues and expected optimum accuracy in 2006 and the future., Comment: 10 pages, PSTP07 proceedings contribution

Optical energy band gap of nanocrystalline NiCr0.8Fe1.2O4 ferrite have been studied. The nanocrystalline NiCr0.8Fe1.2O4 ferrite have been synthesized using sol‐gel technique. X‐ray diffraction pattern confirms the formation of spinel structure in single phase and the average particle size is 4 nm. The energy band gap measurements of nanocrystalline NiCr0.8Fe1.2O4 ferrite in pellet form have been carried out by absorption spectra using double beam spectrophotometer. A pellet of nanoparticle ferrite was made under a load of 10 tons. From the analysis of absorption spectra, nanocrystalline NiCr0.8Fe1.2O4 ferrite have been found to have energy band gap of 3.2 eV at room temperature.

V404 Cyg is a black hole binary which has remained in the low/hard, quiescent X‐ray state for several years, while still being quite variable at all wavelengths on timescales of hours. The optical and X‐ray variability are highly correlated, and interpreted in terms of rapid changes in the irradiation of the accretion disk. Here we present the results of simultaneous radio observations with arcsecond (Very Large Array) and milliarcsecond (Very Long Baseline Array) angular resolution. While the low‐resolution data show V404 Cyg varying on timescales of roughly an hour between 0 and 1 mJy, the high‐resolution data yield no detections, with a typical rms noise of 0.125 mJy/beam in an hour. The combined result implies that the source must be larger than ∼1 mas, corresponding to 4(d/4 kpc) AU. The steady emission has a much lower surface brightness than previously imaged outflows in other X‐ray binaries, while the non‐detection of the flare emission may be due to a high outflow speed (≳0.6(d/4 kpc)c). Either t...

In the present work, Differential Scanning Calorimetry (DSC) has been performed at different heating rates under non‐isothermal conditions to study the crystallizalion kinetics of the Ge0.5Sn0.5Se2.5 chalcogenide glass. Four different methods of analysis (Kissinger equation, Ozawa equation, Matusita equation and Augis and Bennett method) of the non‐isothermal DSC data and various kinetic parameters i.e the activation energy of glass transition (Et), the activation energy of crystallization (Ec), order parameter, rate constant, frequency factor have been determined. The rate constant K (indicator of the rate of to crystalline phase transformation) has been evaluated using the method of Augis and Bannett. Further, the rate of crystallization and dimensionality of growth has also been investigated for the above system.

Precise measurements of the single spin asymmetry, $A_N$ and the double spin asymmetry, $A_{NN}$, in proton-proton (\textit{pp}) elastic scattering in the region of four-momentum transfer squared $0.001 < -t < 0.032 ({\rm GeV}/c)^2$ have been performed using a polarized atomic hydrogen gas jet target and the RHIC polarized proton beam at 24 GeV/$c$ and 100 GeV/$c$. The polarized gaseous proton target allowed us to achieve the measurement of $A_{NN}$ in the CNI region for the first time. Our results of $A_N$ and $A_{NN}$ provide significant constraints to determine the magnitude of poorly known hadronic single and double spin-flip amplitudes at this energy., 4 pages

The Relativistic Heavy Ion Collider at Brookhaven National Laboratory provides polarized proton beams for the investigation of the nucleon spin structure. For polarimetry, carbon-proton and proton-proton scattering is used in the Coulomb nuclear interference region at small momentum transfer ($-t$). Fast polarization measurements of each beam are carried out with carbon fiber targets at several times during an accelerator store. A polarized hydrogen gas jet target is needed for absolute normalization over multiple stores, while the target polarization is constantly monitored in a Breit-Rabi polarimeter. In 2005, the jet polarimeter has been used with both RHIC beams. We present results from the jet polarimeter including a detailed analysis of background contributions to asymmetries and to the beam polarization., 4 pages, 2 figures. to appear in the proceedings of the 17th International Spin Physics Symposium (SPIN 2006), Kyoto, Japan, 2-7 Oct. 2006

The polarized hydrogen Jet target at RHIC continues its mission to provide absolute calibration for the polarized proton beam polarimeters at RHIC. Data were collected at incoming beam momenta of 100, 24, and 32 GeV/c respectively. The statistical and systematic accuracy of the jet data at 100 GeV/c achieved its goal of statistical accuracy of measuring the beam polarization to 3% in Run 5. Attempts at reducing the jet systematic uncertainty due to molecular hydrogen are also described.

The 2005 run (RUN05) was the first extended operation of the polarized RHIC‐pp program. Throughout 3 months of running, polarization measurements were regularly executed every 2 ∼ 3 hours during the beams at storage energy 100GeV using RHIC pC‐polarimeters. These measurements were performed under different beam conditions, i.e., intensity, emittance, backgrounds, cumulated radiation damage on detectors and so on. The stability of measurements under these various conditions is a major concern and is discussed in detail.