Various Kinds Of Substrates Research Articles

CHARACTERISTICS OF CH4/CF4 PLASMA AND FORMATION OF DIAMOND-LIKE CARBON FILMS

CH 4/ CF 4 mixture gas plasmas were studied by a heated double probe method (HDPM) and the relation among plasma states, chemical reaction in the plasma and the characteristics of deposited films was investigated. Electron temperature determined by HDPM had a sharp minimum at the flow rate ratio of CH 4/ CF 4 = 1.8. At high discharge current (200 mA), a hard carbon film with amorphous structure was formed on various kinds of substrates. From the plasma mass spectra, HF molecules were found to play an important role in the plasma reaction and a stoichiometric reaction model was proposed. The unusual variation of the electron temperature was discussed on the basis of the reaction model.

A Method for Evaluating Birefringence in Plastic Substrates of Magneto-optical Disks

A simple method for evaluating birefringence in plastic substrates for magneto-optical disks is proposed. Various kinds of substrates are characterized by this method and the results are discussed in connection with magneto-optical properties.

Low temperature epitaxy by ionized-cluster beam

Ionized cluster beam deposition offers the capability of introducing useful kinetic energy and chemical activity during film formation processes. This allows high quality epitaxy of materials at low temperature onto a wide variety of substrate surfaces and even permits the formation of thin film materials not previously possible. Capabilities are demonstrated by epitaxial Al films on various kinds of substrates, very large area deposition of GaAs, composition controlled Cd1−xMnxTe films, and CdTe/PbTe multilayer epitaxial films.

Ｆｅ３Ｏ４‐γＦｅ２Ｏ３中間酸化膜の保磁力に及ぼす内部応力の影響

The influence of stress on the coercivity of Fe3O4-γFe2O3 intermediary films has been studied. In order to induce various stresses, intermediary films were prepared on various kinds of substrates which had different thermal expansion coefficients. The surfaces of the substrates were coated with an SiO2 layer prior to the film preparation in order to eliminate the difference in their chemical properties. The magnetic properties and plane distances of the Fe3O4-γFe2O3 intermediary films were measured. Films prepared on the substrates having smaller thermal expansion coefficients showed larger coercivity increases. A remarkable increase in coercivity was obtained only when the stress in the film was in tension.

Analysis of electrical properties of amorphous silicon films in distinct local environments by the ebic method

It has been confirmed that the Electron Beam Induced Current (EBIC) technique is effective for the investigation of amorphous Si (a-Si) properties. Appling the EBIC method to an analysis of a-Si properties, it is possible to investigate the fine property distribution with two-dimensional information at a distinct local environment. EBIC images of a-Si films on various kinds of substrates were obtained with the limit of the resolution being about 0.5 μm. The fine property distribution indicated by the EBIC image corresponds well with the unevenness of the surface of a-Si films. Therefore, it has been possible to carry out a morphological study and a property investigation of a-Si films by the EBIC technique.

Effect of surface acidity of activated carbons on their characteristics of adsorption from the vapour phase—comparison of retention time for carbons used as adsorbents for gas chromatography

Seventeen kinds of activated carbons of different surface acidity and of known pore-structure were used as adsorbents for gas chromatography. The retention time of various kinds of substrates was determined for each carbon at different temperatures. It was found that surface acidity of carbons has a marked effect on increasing the retention time for polar substances while showing no effect for non-polar substances. Retention times varied with temperature which suggested, when the effect of surface acidity is taken into account, that the pores which were effective for the Chromatographic adsorption have been determined by the temperature. The heat of adsorption calculated on the basis of the retention times observed at different temperatures showed an inverse correlation with dielectric constant of the adsorbates.

Sputtering and chemical vapour deposition of piezoelectric ZnO, AlN and K 3Li 2Nb 5O 15 films for optical waveguides and surface acoustic wave devices

Epitaxial and c-axis-oriented ZnO thin films with surface flatness were successfully grown on various kinds of substrate by r.f. planar magnetron sputtering, ZnOH 2H 2OO 2 isothermal chemical vapour deposition (CVD) and plasma-enhanced organometallic CVD methods. c-axis-oriented AlN films were also prepared on glass and silicon substrates at substrate temperatures as low as 20–460°C by reactive r.f. planar magnetron sputtering. Furthermore, ferroelectric K 3Li 2Nb 5O 15(KLN) crystal films were grown with good epitaxy on K 2BiNb 5O 15 or sapphire substrates by sputtering. The quality of the ZnO, AlN and KLN films was evaluated from X-ray diffraction, scanning electron microscopy and reflection electron diffraction measurements. These films are excellently transparent and are of extremely good quality. The epitaxial CVD and c-axis-oriented sputtered ZnO films have guided optical wave losses as low as 0.7 dB cm −1 and 2.1 dB cm −1 respectively. All the films are piezoelectrically active and show surface acoustic wave response.

Enzymatic properties of neuraminidases from Arthrobacter ureafaciens.

Neuraminidase I and neuraminidase II from Arthrobacter ureafaciens were characterized. As determined by gel filtration on Ultrogel AcA 44, the molecular weights of neuraminidases I and II were 51,000 and 39,000, respectively. Neuraminidases I and II were similar to each other in their enzymatic properties except for the substrate specificities towards gangliosides and erythrocyte stroma. Their optimal pHs were between 5.0 and 5.5 with N-acetylneuraminosyl-lactose or bovine submaxillary mucin as substrates, but with colominic acid as a substrate, the pH optimum was between 4.3 and 4.5. They were most active around 53 degrees C, were stable between pH 6.0 and 9.0, and were thermostable up to 50 degrees C. They did not require Ca2+ for activity and were not inhibited by EDTA. They were inhibited only slightly or not at all by p-chloromercuribenzoic acid of Hg2+. Both neuraminidases I and II were able to hydrolyze the alpha-ketosidic linkage of N-glycolylneuraminic acid as well as that of N-acetylneuraminic acid, and were able to liberate substantially all of the sialic acid from various kinds of substrates. However, they cleaved only about 50% of the sialic acid from bovine submaxillary mucin. The saponification of bovine submaxillary mucin by mild alkali treatment, on the other hand, resulted in an increased susceptibility to the neuraminidases and brought about the complete liberation of sialic acid. Remarkable differences were observed between neuraminidases I and II as regards substrate specificities on gangliosides; the initial rate of hydrolysis by neuraminidase I was 74 times, and its maximum velocity constant was 91 times those of neuraminidase II. The addition of sodium cholate markedly stimulated the enzymatic hydrolysis of gangliosides, and increased the maximum velocity constant of neuraminidase I twofold and that of neuraminidase II 143-fold. Although neuraminidases I and II were able to hydrolyze (alpha,2-3), (alpha,2-6), and (alpha,2-8) linkages, the initial rate of hydrolysis of N-acetylneuraminosyl-alpha,2-6-lactose was greater than that of the alpha,2-3-isomer.

Elastase-like enzymes in aortas and human breast carcinomas: quantitative variations with age and pathology.

Two neutral proteases have been isolated from aortas and human breast tumors. The aortic elastase-like enzyme has been further purified. The details of this purification procedure will be given and some of the properties of the purified enzyme (susceptibility to various kinds of substrates, degree of inhibition of serum inhibitors, alpha 1-antitrypsin and alpha 2-macroglobulin). This elastinolytic activity of the aorta increased with age and with the degree of atherosclerosis. Both parameters seem to act independently and in a cumulative fashion. Elastinolytic activity has been demonstrated in extracts of human breast carcinomas and is exponentially related to the age of the patient. There exists a parallel neosynthesis of elastin which increased also with the age of the patient. Some characteristics of the polymeric elastin isolated from the tumor tissue will be given. The possible role of this neutral protease present in human aortas and human breast carcinomas will be discussed.