Advanced Materials Research Vol. 893

Abstract: Diamond-like carbon (DLC) films and nitrogen doped DLC (NDLC) were deposited on glass slide and H13 steel by plasma-enhanced chemical vapor deposition using a commercial RF 13.56 MHz (RF-PECVD). The films have been prepared from CH₄ for DLC and CH₄+N₂ mixtures for NDLC. The deposition process was at 300°C under argon atmosphere for 120 min. Bonding energy and diamond like carbon characteristic of DLC and NDLC films have been characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Raman spectroscopy. Thermalgravimetric Analyzer (TGA) was used to evaluate the thermal stability of the films which were scrapped off from a glass slide substrate. The mechanical properties was characterized, such as hardness by nanoindentation technique, scratch test by Rockwell diamond tip in progressive mode and friction coefficient have been measured in ambient air using a ball-on-disk tribometer.

Abstract: The porous silica thin film was selected as thermal insulation thin film of uncooled infrared detector in order to reduce device thermal conduction loss. A new ion implantation manufacture method of porous silica thin film was studied in this paper. The porous silica thin films were prepared by ion implanted method and acid/alkali two-step catalytic sol-gel method respectively for comparison purpose. H⁺ and N⁺ ion mixing implantation technique adopted makes the gas bubble in the depth and shallow of silica thin film respectively, and one setting power can form porous structure with porous rate between 17% and 29%. By properly control the heat dealing process, gas bubble will format, expand, but not abrupt in the silica thin film. Sol-gel derived silica thin film has porous rate of 62.8%, but it cannot be used as substrate of electrode film and infrared thermal sensing film because of its irregular surface. The surface of ion implanted silica thin film is even and can be used as substrate, and its insulating performance could be further enhanced by etch off the thick silica substrate from back, after pyroelectric infrared sensing layer formed.

Abstract: Nanocrystalline ZnO films were deposited by rf reactive magnetron sputtering. The films were characterized by reflection high-energy electron diffraction, X-ray photoelectron spectroscopy and gas sensing measurements. It was found that annealing of the film enabled to invert its conductivity type. Thus, as-deposited ZnO film showed p-type conductivity while annealed film showed n-type conductivity behavior. The p-and n-type conductivities of the films obtained by gas sensing measurements have been confirmed by XPS results. The gas sensing properties of the films were investigated upon exposure to 10 ppm of NO₂ at 22°C and exhibited good sensitivity with fast response and recovery times. The sensor response to NO₂ was found to be profoundly dependent on the conductivity behavior of the film.

Abstract: In this work, the effect of different interlayer elements on the properties of the top AlCrTiSiN film, i.e. titanium and chromium called as Ti/AlCrTiSiN and Cr/AlCrTiSiN, respectively, was studied. The film was deposited by cathodic arc physical vapor deposition on tungsten carbide (WC) specimen which is extensively used as cutting tools material. Various properties including the surface hardness, the scratch resistance and tribological performance were later studied. The surface hardness of both Ti/AlCrTiSiN and Cr/AlCrTiSiN coatings were higher than 29 GPa. The critical load for both coating suggesting supurb adhesion strength of the coating system. However, Ti interlayer was found to result in higher critical compressive stress for first damage and full delamination at room temperature. The wear resistance of coated specimens was far better than the uncoated one both at room temperature and high temperature, i.e. ball on disc tests at room temperature, 300 °C, and 500 °C were performed. The coeeficient of friciton of both coatings were found to depend strongly on the wear behavior of the system and the characters of the wear debris. A sign of better tribological performance at high temperature, i.e. 500°C, could be noticed with Cr interlayer as the lower mismatch in coefficient of thermal expansion became more crucial in film damage phenomina at such temperature.

Abstract: Barium strontium titanate becomes famous among the microelectronic field due to its dielectric properties. Sol-gel method was used to prepare the Ba _0.6Sr _0.4TiO₃ and was deposited on SiO₂ substrate. The temperatures used in the heat treatment process were high temperature, 650°C. For high heat treatment temperature, the process was carried in 2 different times which were 15 min and 60min.The effect of the different temperature and time in the heat treatment process were analysed by using XRD. 650°C for 15 min and 60min, there are clearer peaks observed and the intensity of the 110 peak was sharper.

Abstract: 1-10% (atomic ratio of Al/Sn) Aluminium-doped tin oxide (SnO₂:Al) single crystalline films were prepared on α-Al₂O₃ (0001) substrates by the metalorganic chemical vapor deposition (MOCVD) method. The films were annealed in air at 400 °C, 700°C, 800°C and 900°C, respectively. The structural, electrical and optical properties of the samples were investigated. The obtained films were rutile structure with high a-axis orientation. The Hall mobility and carrier concentration of the samples were varied with the Al concentration increasing and different anneal temperature. The average transmittance for the SnO₂:Al films in the visible range was over 82% and the absorption edge shifted to the shorter wavelength with Al concentration increasing. The position of Al3+ in the lattice was influenced by anneal temperature. After high temperature annealed, the location of SnO₂ (200) diffraction peak shifted slightly towards low 2θ direction which was due to the lattice relaxation, and the absorption edge of the films shifted to the shorter wavelength because of the Burstein-Moss effect.

Abstract: High quality crystalline zinc-stannate transparent conducting films were successfully prepared on sapphire substrates by MOCVD method. ZnSnO films with the proportions of tin and zinc from 1: 1 to 1:20 were prepared and ZnSnO ₃ films were obtained when the proportion is 1:1. The structural, optical and electrical properties of zinc-stannate films were investigated.

Abstract: Indium Tin Oxide (ITO) is a transparent conducting material. The particular electrical and optical properties of the ITO make it becomes an important material that being applied in optoelectronic filed. In this paper, investigation on various parameters in time of deposition and ITO layer on specimen was done. The AFM (Atomic Force Microscope) was used to investigate grain size on specimen. It shows more layer deposition of ITO, it will increase grain size on the specimen. In addition, grain size on specimen was increased after annealing process compared test specimen before annealing process. Besides that, semiconductor parametric analyser was used to examine resistance on ITO films. The higher value of resistance is showed on test specimen after heat treatment compared to test specimen before heat treatment.

Abstract: ZL101A Al-Si Alloy was processed of anode oxidation by DC Pulsed power, the film thickness and micro-structure were investigated with the electrolyte concentration, oxidation time and other technical parameters; the chemical composition of the film, the phase composition and the micro-hardness were tested. The results showed that the better technical parameters of making oxide film were:anode voltage was 16 V, current density was 1 A/dm², sulfuric acid concentration was 140 g/L, oxidation time was 30 min, film thickness was 12 μm; the Al phase, Si phase and β-Al₂O₃ phase were showed by XRD of the film; and the micro-hardness of the film was 288 HV_0.05.

Abstract: In order to study the asphalt pavement testing compaction technology accuracy with the non-nuclear density gauge. Pave TrackerTM Plus 2701-B is used to research the influence of temperature and humidity, and Construction dynamic detection technology and methods is established basing on 2701-B,And the type of mixture was studied. It is found that, because of the difference of temperature and humidity, the result of Compaction degree has the large variability, the increased with temperature and humidity, especially humidity affects more significant. Finally, the non-nuclear detection technology method of asphalt pavement is established, this paper presents adopting the temperature and humidity compensation or increasing the number of calibration samplesisand and testing used to make up accuracy, which can effectively improve the service performance of airport asphalt pavement.