EFFECTS OF SPUTTERING CONDITIONS OF Tb Fe Co MAGNETO OPTICAL FILM ON KERRR OTATION

In the practical magneto opticaldisk productionline,alloysputteringtargetisalwaysusedtosputter recording film , whileinlaid targetisrarely used .In ourlaboratory,a seriesof al loy targets forsputtering magneto- optical recording film were prepared and theeffect ofcomposition andsputtering parameterson magneto opticalpropertiesarestudied . Thesputter ing rateof Al,Siand Tb Fe Co( Mo) undertheconditionsof differentsputtering powerandN2 Argasflux weredetermined and baseontheresults,a variablecomposition andthickness of SiNcan beobtained by meansof regulating sputtering power and gasflux, kindsof Mosputtering filmsareobtained under differentsputtering power and gasflux, and Kerrloop lineofthese magneto opticalfilmsare measuredto acquiretheir propertiessuch as Kerrrota tion,then ,theeffectofsputteringtechnology on Kerrrotationisdiscussed .

A Fiber Optic Sensor for 2,4-dichlorophenol Analysis based on Optical Composite Oxygen-sensitive Film

A novel fiber optic sensor based on optical composite oxygen-sensitive film was developed for determination of 2,4-dichlorophenol(DCP).The optical composite oxygen-sensitive film consists of tris(2,2’-bipyridyl)dichloro ruthenium(II)hexahydrate(Ru(bpy)3Cl2)as the fluorescence indicator and iron(III)tetrasulfophthalocyanine(Fe(III)PcTs)as bionic enzyme.A lock-in amplifier was used for detecting the lifetime of the composite oxygen-sensitive film by measuring the phase delay of the sensor head.The different variables affecting the sensor performance were evaluated and optimized.Under the optimal conditions(i e,pH 6.0,25℃,Fe(III)PcTs concentration of 5.0×10^-5 mol/L),the linear detection range,detection limit and response time of the fiber optic sensor are 3.0×10^-7-9.0×10^-5 mol/L,4.8×10^-8 mol/L(S/N=3),and 220 s,respectively.The sensor displays high selectivity,good repeatability and stability,which have good potentials in analyzing DCP concentration in practical water samples.

Electrical and Optical Properties of GaSe Thin Films

The structure, electrical transport, and optical properties of GaSe films fabricated by means of radio-frequency (RF) magnetron sputtering in Ar were investigated. The as-sputtered GaSe films were amorphous, and their optical energy gap Eg are 1.9～2.6 eV. The effect of the synthesis conditions on the optical and electrical properties of the GaSe films has also been studied

The Third-Order Nonlinear Optical Properties in Cobalt-Doped ZnO Films

We quantitatively investigate the third-order optical nonlinear response of Co-doped ZnO thin films prepared by magnetron sputtering using the Z-scan method. The two-photon absorption and optical Kerr effect are revealed to contribute to the third-order nonlinear response of the Co-doped ZnO films. The nonlinear absorption coefficient β is determined to be approximately 8.8 × 10-5 cm/W and the third-order nonlinear susceptibility X（3） is 2.93 × 10-6 esu. The defect-associated energy levels within the band gap are suggested to be responsible for the enhanced nonlinear response observed in Co-doped ZnO films.

The determination of the thickness and the optical dispersion property of gold film using spectroscopy of a surface plasmon in the frequency domain

We propose to use wavelength modulation approach,i.e.,the spectroscopy of a surface plasmon in the frequency domain,to characterize the optical dispersion property of gold film.Using this method,we determine the dispersion relationship of gold film in a wavelength range from 537.12 nm to 905.52 nm,and our results accord well with the reported results by other authors.This method is particularly suited for studying the optical dispersion properties of thin metal films,because a series of dielectric constants over a wide spectral range can be determined simultaneously via only a single scan of the incident angle,thereby avoiding the repeated measurements required when using the angular modulation approach.

Optical properties of titanium oxide films obtained by cathodic arc plasma deposition

Structural and optical properties of nanometric titanium oxide（TixOy） films obtained by cathodic arc plasma deposition were investigated. Phase analysis by x-ray diffraction and Fouriertransform infrared spectroscopy showed the presence of anatase, rutile, Ti_2O_3, Ti_4O_7 and amorphous phases. Scanning electron microscopy images showed well-developed surface morphology with nano-patterns. Spectroscopic ellipsometry revealed film thicknesses of 53 and50 nm, variable refractive indices dependent on the light wavelength and close to zero extinction coefficients for wavelengths higher than 500 nm. On the basis of ultraviolet–visible spectroscopy data and using the Tauc equation, band gap values for direct and indirect electron transitions were determined.

Structural, Optical and Luminescence Properties of ZnO Thin Films Prepared by Sol-Gel Spin-Coating Method： Effect of Precursor Concentration

Transparent zinc oxide（ZnO） thin films are fabricated by a simple sol-gel spin-coating technique on glass substrates with different solution concentrations（0.3-1.2 M） using zinc acetate dehydrate [Zn（CH_3COO）_2·2H_2O] as precursor and isopropanol and monoethanolamine（MEA） as solvent and stabilizer, respectively. The molar ratio of zinc acetate dehydrate to MEA is 1.0. X-ray diffraction, ultraviolet-visible spectroscopy and photoluminescence spectroscopy are employed to investigate the effect of solution concentration on the structural and optical properties of the ZnO thin films. The obtained results of all thin films are discussed in detail and are compared with other experimental data.

Effect of Oxygen Concentration and Annealing Theatment on the Optical Properties of the Transparent Conductive CdIn_2O_4 Thin Films

Transparent conductive cadmium indium oxide films (CdIn2O4) were prepared by r.f. reactive sputtering from Cd-In alloy targets under an Ar-O2 atmosphere. Electrical conductivity of the order of 105Ω-1.m-1 and the optical transmission as high as 94% are easily attained by postdeposition annealing treatment. The effects of oxygen concentration in the reactive gas mixture and post-deposition annealing treatment on the optical transmittance as well as optical parameters, such as refractive index (n), extinction coefficient (k), real part (ε') and imaginary part (ε') of the dielectric constant, were studied in the visible and near-infrared region. The highfrequency dielectric constant ε∞ the plasma frequency ωP, and the conduction band effective mass mc of different samples were also investigated

Photoinduced Reorientation Process and Nonlinear Optical Properties of Ag Nanoparticle Doped Azo Polymer Films

Azobenzene polymer films doped with and without Ag nanoparticles are prepared. The photoinduced reorientation process is investigated by using an Nd：YVO4 pump beam at 532 nm and a low semiconductor laser beam at 650 nm. The reorientation rate of azo polymer films is enhanced in the presence of Ag nanoparticles, and the rate of the azo polymer film with Ag concentration of 2.2 μg/ml is larger than that of the azo polymer films with Ag concentrations of 1.1 μg/ml and 4.4 μg/ml. The third-order nonlinear optical properties of the Ag/azo composite film are obtained by the Z-scan technique at a wavelength of 532 nm, and the measured nonlinear refractive index is 9.258×10-9 esu. It is shown that the main mechanisms involved in the large nonlinear optical responses come from the local field enhancement of Ag nanoparticles and the nonlinear effect of the azo polymer matrix.

Structural, Optical and Electrical Properties of Evaporated CdSe Films

CdSe films are of great interest for use in thin film photoelectric devices. A simple chemical precipitation method is adopted for the first time to synthesise CdSe powder. Films on glass obtained at different substrate temperatures TS such as 300, 373, 423 and 473 K have been characterised by X-ray diffraction, optical absorption and Hall measurements.

Dependence of Nitrogen/Argon Reaction Gas Amount on Structural,Mechanical and Optical Properties of Thin WNx Films

WNxfilms are deposited by reactive chemical vapor deposition at different amounts of nitrogen in gas mixtures.Experimental data demonstrate that nitrogen amount has a strong effect on microstructure, phase formation,texture morphology, mechanical and optical properties of the WNxfilms. With increasing nitrogen a phase transition from a single WNxphase with low crystallinity structure to a well-mixed crystallized hexagonal WNxand face-centered-cubic W2N phases appears. Relatively smooth morphology at lower N2concentration changes to a really smooth morphology and then granular with coarse surface at higher N2concentration. The SEM observation clearly shows a columnar structure at lower N2concentration and a dense nanoplates one for higher nitrogen content. The hardness of WNxthin films mainly depends on the film microstructure. The absorbance peak position shifts to shorter wavelength continuously with increasing nitrogen amount and decreasing particle size.

Microstructure and optical properties of nitrogen-doped ZnO film

The nitrogen doping of ZnO film deposited by the magnetron sputtering method is subsequently realized by the hydrothermal synthesis method.The nitrogen-doped ZnO film is preferably（002） oriented.With the increase of hexamethylenetetramine（HMT） solution concentration,the average grain size of the film along the 002 direction almost immediately decreases and then monotonously increases,conversely,the lattice strain first increases and then decreases.The structural evolution of the film surface from compact and even to sparse and rough is attributed to the enhanced nitrogen doping content in the hydrothermal process.The transmission and photoluminescence properties of the film are closely related to grain size,lattice strain,and nitrogen-related defect arising from the enhanced nitrogen doping content with HMT concentration increasing.

Relationship Between Thermal Stability and Optical Bandgap of Fluorinated Amorphous Carbon Films

Fluorinated amorphous carbon films were deposited using microwave electron cyclotron resonance chemical vapor deposition (ECR-CVD) reactor with CF4 and C8H6 as source gas and were annealed in nitrogen ambience for the investigating of their thermal stability .The relative concentration of C=C bond and optical bandgap were obtained by Fourier Transform Infrared (FTIR) spectroscopy and Ultraviolet-Visible (UV-VIS ) spectrum, respectively. It has been demonstrated that there is a close relationship between relative concentration of C=C bond and optical bandgap, and the films deposited at a higher microwave power have a lower optical bandgap and a better thermal stability.

Effect of Pre-heating Temperature on Structural and Optical Properties of Sol-gel Derived Zn_(0.8)Cd_(0.2)O Thin Films

Zn_（0.8）Cd_（0.2）O thin films prepared using the spin-coating method were investigated. X-ray diffraction, scanning electron microscopy, and UV-Vis spectrophotometry were employed to illustrate the effects of the pre-heating temperature on the crystalline structure, surface morphology and transmission spectra of Zn_（0.8）Cd_（0.2）O thin films. When the thin films were pre-heated at 150 ℃, polycrystalline Zn O thin films were obtained. When the thin films were pre-heated at temperatures of 200 ℃ or higher, preferential growth of Zn O nanocrystals along the c-axis was observed. Transmission spectra showed that thin films with high transmission in the visible light range were prepared and effective bandgap energies of these thin films decreased from 3.19 e V to 3.08 e V when the pre-heating temperature increased from 150 ℃ to 300 ℃.

New method for fast morphological characterization of organic polycrystalline films by polarized optical microscopy

A new method to visualize the large-scale crystal grain morphology of organic polycrystalline films is proposed. First,optical anisotropic transmittance images of polycrystalline zinc phthalocyanine（Zn Pc） films vacuum deposited by weak epitaxial growth（WEG） method were acquired with polarized optical microscopy（POM）. Then morphology properties including crystal grain size, distribution, relative orientation, and crystallinity were derived from these images by fitting with a transition dipole model. At last, atomic force microscopy（AFM） imaging was carried out to confirm the fitting and serve as absolute references. This method can be readily generalized to other organic polycrystalline films, thus providing an efficient way to access the large-scale morphologic properties of organic polycrystalline films, which may prove to be useful in industry as a film quality monitoring method.

Gap States of ZnO Thin Films by New Methods:Optical Spectroscopy,Optical Conductivity and Optical Dispersion Energy

The optical reflectance and transmittance spectra in the wavelength range of 300-2500 nm are used to compute the absorption coefficient of zinc oxide films annealed at different post-annealing temperatures 400, 500 and 600°C.The values of the cross point between the curves of the real and imaginary parts of the optical conductivity ɑ_1 and ɑ_1 with energy axis of films exhibit values that correspond to optical gaps and are about 3.25-3.3 eV. The maxima of peaks in plots dR/dλ and dT/dλ versus wavelength of films exhibit optical gaps at about 3.12-3.25 eV.The values of the fundamental indirect band gap obtained from the Tauc model are at about 3.14-3.2 eV. It can be seen that films annealed at 600°C have the minimum indirect optical band gap at about 3.15 eV. The films annealed at 600°C have Urbach＇s energy minimum of 1.38 eV and hence have minimum disorder. The dispersion energy d of films annealed at 500°C has the minimum value of 43 eV.

Brightness of Blue/Violet Luminescent Nano-Crystalline AZO and IZO Thin Films with Effect of Layer Number:For High Optical Performance

From different reports, it （AZO） and indium-doped including usage areas. We nanocrystalline films with is realized that there is a need to consider all sides of aluminum-doped zinc oxide zinc oxide （IZO） thin films with their optical, luminescence and surface properties establish an assessment to carry out further information to summarize AZO and IZO impact of the layer number.

RESONANT PHOTOEMISSION OF BULK CeO_(2) AND NANO-CeO_(2) FILMS

Photoemission behaviors of nano-CeO2 films with particle sizes ranging from 8 nm to 50 nm and bulk CeO2 in Ce 4 d-4 f absorption region have been investigated. Resonant enhancements of Ce 4 f valance band and Ce 5 p bands for nano film and bulk material have been observed. The variation of electron density of states in valance bands of nano and bulk structures of CeO2 is discussed in terms of Ce 4 d-4 f resonance.

Microstructure Control of Nanoporous Silica Thin Film Prepared by Sol-gel Process

Nanoporous silica films were prepared by sol-gel process with base, acid and base/acid two-step catalysis.Transmission electron microscope （TEM） and particle size analyzer were used to characterize the microstructure and the particle size distribution of the sols. Scanning electron microscopy （SEM）, atomic force microscopy （AFM） and spectroscopic ellipsometer were used to characterize the surface microstructure and the optical properties of the silica films. Stability of the sols during long-term storage was investigated. Moreover,the dispersion relation of the optical constants of the silica films, and the control of the microstructure and properties of the films by changing the catalysis conditions during sol-gel process were also discussed.

Phase shift of polarized light through sculptured thin films: Experimental measurements and theoretical study

A slanted columnar TiO2 sculptured anisotropic thin film （ATF） is prepared via the glancing angle deposition technique and used as the phase retardation plate. The tilted nanocolumn microstructures of thin film induce the optical anisotropy. With the biaxial birefringent model, the optical constants dispersion equations of TiO2 ATF are derived by fitting the transmittance spectra for s-and p-polarized waves measured at normal and oblique incidence within 400 nm–1200 nm. The phase shift of polarized light after reflection and/or transmission through the TiO2 ATF is analyzed with the characteristic matrix employing the extracted structure parameters. The theoretical studies reasonably well accord with the experimental results measured with spectroscopic ellipsometry. In addition, the dependences of the phase shift on the coating physical thickness and oblique incidence angle are also discussed. Birefringence of the biaxial ATF provides a sophisticated phase modulation by varying incidence angles over a broad range to have a wide-angle phase shift.