Kiyoshi Chiba

Production and Properties of Transparent Electroconductive Coating on Polyester Film

Indium oxide was vacuum deposited onto the surface of polyester films. The oxide is reduced to In2O by sublimation and a thin opaque electroconductive coating is obtained. The coating was thermally oxidized in the air below 200°C. The resulting film showed transmission of 80 to 95% for visible light and surface resistance of 200 to 500 ohm/sq. Small amount of stannic oxide doped to the indium oxide improves the surface resistance and determines the optimum temperature of the substrate. The mechanism of formation and the properties of the coating were discussed.

Fabrication and Optical Properties of Low-Emissivity Coatings of AlSiN and AgCuNd-Alloy Multilayer Films on Glass

Transparent low-emissivity coatings comprised of AlSiN and Ag-alloy multilayer films were investigated. All films were prepared by dc magnetron sputtering. AlSiN/Ag-alloy/AlSiN/Ag-alloy/AlSiN multilayer films were prepared on glass substrates. Three types of Ag-alloys were used: Ag87.5Cu12.5, Ag88Au4.6Cu7.3Ti0.1, and Ag95.8Cu2.2Nd2 films. Thicknesses of the Ag-alloy films were controlled to be in the range of 10–12 nm thick. Compared to the AgCu- and AgAuCuTi-alloys, the AgCuNd-alloy films showed superior optical properties. The maximum transmittance (Tmax) was 85.6% for multilayer coatings with 10-nm-thick Ag95.8Cu2.2Nd2-alloy films. The maximum transmittance is 4 and 7% higher than for the coatings with Ag89.5Au7Cu3Ti0.5- and Ag87.5Cu12.5-alloy films, respectively. In the case of AlSiN (43 nm)/Ag95.8Cu2.2Nd2 (11 nm)/AlSiN (86 nm)/Ag95.8Cu2.2Nd2 (11 nm)/AlSiN (43 nm) multilayer coatings, 79.7% visible light transmission (Tvis) and a shading coefficient of 0.50 were obtained. This indicates that well-balanced transparent low-emissivity coatings with both high visible transparency and good solar infrared shading can be produced for multilayer coatings with the AgCuNd-alloy films.

Improved Optical Properties of Transparent Low-Emissivity Coatings Using an Asymmetrical Structure Containing Two Silver-Alloy Layers

Transparent low-emissivity coatings of AlSiN/Ag99.1Mg0.5Eu0.4 alloy (1)/AlSiN/Ag99.1Mg0.5Eu0.4 alloy (2)/AlSiN films using the environmentally robust AgMgEu alloy and the AgMgEu-alloy (2) layer thicker than the AgMgEu-alloy (1) layer were developed. The optical properties of the films were improved when the second Ag-alloy layer was 1.2 to 2.0 times thicker than the first Ag-alloy layer. Specifically, they had a sharp cut-off for near-infrared light from the sun while retaining a high visible transmittance. A visible transmittance of 80% and a shading coefficient of 0.45, corresponding to a reflectance of 77% at a wavelength of 850 nm were realized for glass/AlSiN (47 nm)/AgMgEu (11 nm)/AlSiN (94 nm)/AgMgEu (18 nm)/AlSiN (47 nm) films.

Use of a coil atomizer in metastable transfer emission spectroscopy

Abstract Metastable transfer emission spectroscopy associated with a compact tungsten coil atomizer was carried out for cadmium detection. A pulse atomization induced by a capacitor discharge to a coil-producing condensed vapor which was transported and mixed with active nitrogen generated by microwave discharge. High sensitivity of emission for the short time duration of approximately 60 ms was observed in this system. Elemental cadmium in 5 μl nitric acid solution was deposited on a coil with a detection limit of less than 5 pg at 326.1 nm. The linearity of the calibration curve for cadmium extended from 5 to 200 pg, beyond which the intensity of the emission signal was saturated. The system was insensitive to interference by coexisting elements; the emission of cadmium was unaffected up to a factor of more than 10, particularly 200 for lead.

Magnetic and magneto-optical properties of CoPtM (M=Re, Ru) alloy films for a new magneto-optical recording material

Abstract CoPtM (M = Re, Ru) ternary alloy films have been investigated as new magneto-optical materials for blue laser recording. The CoPtRe and CoPtRu alloy films were prepared by sputtering without a heating process, and exhibited good perpendicular magnetic anisotropy and magnetic hysteresis loop squareness. For the magneto-optical properties, the figure of merit for the CoPtRe alloy film with less than 15 at% Re at λ

Sputtered amorphous Fe–Te films: Structural and electrical studies

Thin films of an iron–tellurium alloy were prepared by rf sputtering and characterized by means of x‐ray diffraction and Mossbauer spectroscopy. In an immiscible range in equilibrium composition, tellurium atoms were incorporated into iron, distorting the lattice to some extent. Beyond 14 at. % of Te, an amorphous structure appeared. Judging from the metastable superstructures formed at higher substrate temperatures and the covalent nature in the bonding, the kinetic hindrance against the redistribution of the elements due to the local atomic forces during rapid quenching plays a critical role in the formation of amorphous structure in this alloy. In addition, beyond some intermetallic range around 60 at. % Te, an amorphous phase also exists in the tellurium‐rich region. The thermal stability was examined by a differential scanning calorimetry; the electrical resistivity is also discussed.

Transparent Heat Insulating Coatings On A Polyester Film

Multi-layer coatings of metal-dielectric type were prepared on a poly (ethylene terephthalate) (PET) film using chemical and physical preparation techniques. Hydrolysis of tetrabutyl titanate (TBT) followed by condensation gave rise to well-controlled transparent dielectric layers with relatively high refractive index and a silver layer was prepared by vacuum evaporation. Changes of chemical coating condition gave various types of optical characteristics. This film reduces energy dissipation from a single windowpane by around 35%.

Magneto-optical recording on CoPtRe alloy films as a novel material

Magneto-optical (MO) disks using CoPtRe ternary alloy films have been investigated as a novel recording material for a blue laser recording. For various types of disk structure, the Kerr rotation, the Kerr ellipticity, and the figure of merit were calculated and an optimum structure was estimated. Magneto-optical recordings were made on a CoPtRe MO disk at wavelengths of 830 and 530 nm. The recording properties were almost equivalent to those for Co/Pt multilayers.

Fabrication and optical properties of low-emissivity coatings of indium Tin oxide or AlSiN and Ag-alloy multilayer films on glass

Transparent low-emissivity coatings comprising indium tin oxide (ITO) or AlSiN and Ag-alloy multilayer films were investigated. All films were prepared by dc magnetron sputtering. In ITO/AgCu-alloy/ITO/AgCu-alloy/ITO multilayer films, the spectral selectivity is influenced by the oxygen content of the gas mixture of Ar and O2 during ITO deposition. The visible light transmission (Tvis) of 76.2% and the shading coefficient of 0.51 were obtained for the multilayer films prepared with 1.76 vol.% O2 in the sputtering atmosphere. In AlSiN/AgCu-alloy/AlSiN/AgCu-alloy/AlSiN multilayer films, prepared by reactive sputtering of an AlSi-alloy target in the gas mixture of Ar and N2, the transmittance increased with increasing sputtering power during AlSiN deposition. The results of an Auger electron spectroscopy study suggest that this effect is likely attributed to the formation of AlSiON in the films at low power due to the influence of a residual gas. The emittance from 0.20 to 0.05 at 297 K was obtained for the AlSiN multilayer films with an AgCu-alloy layer of thickness in the range of 6 to 15 nm thick.

Photostructural Change of Chalcogenide Glass Films by Irradiation of Laser Diode Emission

An optical change of As-Se-S-Ge amorphous chalcogenide film was observed by irradiation of a focused beam of laser diode emission of 830 nm wavelength. An optical analysis shows that this change occurs through energy band-tail absorption with an absorption coefficient of less than about 10 cm-1 and through a pure photon process.