A review has been made on studies of the chemical analysis of semiconductors mostly conducted during the last few years. The chemical analysis involves the quantitative and quantitative analysis of impurities, three dimensional distribution of impurities and composition determination in compound semiconductors. These studies employed such methods as radio-activation analysis, nuclear reaction analysis, ion back scattering, electron probe microanalysis, Auger electron spectroscopy, spark source mass spectroscopy, ion microprobe analysis and optical spectroscopies. Finally, a brief summary has been made on the analysis of nonstoichio-metry.
This paper may be devided into three parts. In the first part, optical characteristics of ferroelastic ferroelectric crystals in general are discussed. Subsequent discussion deals with rhombohedral ferroelastic ferroelectric crystals, and their importance as electro-optic memory materials because of their longitudinal bistable optical switching properties. The second part reviews the crystallographic, dielectric, optical and domain switching properties of gadolinum molybdate as a typical rhombohedral ferroeleastic ferroelectric crystal. It also contains a detailed explanation of the construction methods of the domain switching elements. The third part a fabrication technique utilizing a new crystal slicing machine which can cut a crystal precisely along an X-ray determined orientation is introduced. And device applications such as a λ/4 and a λ/2 plates, laser beam shutters, color modulators and digital space modulators are evaluated from a practical standpoint.
Measurements were carried out to find out relations among the depolarization current, polarization current and temperature for purified hexadecane (C16H34), hexadecyl alcohol (C16H33OH), hexadecyl amine (C16H33NH2) and hexadecanoic acid (C15H31COOH). Differential thermal analysis (DTA) was also carried out for the same substances. The polarizing field and temperature used were in a range from 1±103 to 5±104V/cm and above melting point. The depolarization and the polarization currents of these substances showed peaks at the temperatures of crystalline transition and melting. The peak temperatures in the DTA curves were in a good correspondence to those of the depolarization and of the polarization currents. The peak temperatures of the depolarization current were independent of the polarizing field. The total amount of depolarized charge was almost linearly related to the applied field strength. The depth of energy for the trapped ions were estimated as 0.3 to 1.0 eV for the peak at the crystalline transition temperature and above 1 eV for the peak at melting temperature.
In scanned-type holographies, anamorphic holograms are recorded due to the relative movements of the source, object and receiver. In this paper a technique to reconstruct images from such anamorphic holograms is proposed together with a theoretical analysis of the technique. An ultrasonic holography system with a one-dimensional receiver array is considered, where the holograms are constructed by a synthesis of the receiver-scanning and the source-scanning and the reference wave is simulated electrically. It is shown from the theoretical analysis that these holograms are intrinsically anamorphic. An optical processing using a cylindrical lens may be adopted to reconstruct correct images. An experiment using 1 MHz ultrasonic wave is proposed to examine the results of the theoretical discussion.
The 9. 6 μm ozone band is of considerable meteorological interest owing to its importance in the heat balance of the upper stratosphere. In order to obtain spectroscopic data of ozone, we have constructed an ozonizer system using silent discharge at low temperature. This paper describes the ozonizer and the absorption coefficient of the ν3 band of the produced ozone.
This paper describes experimental studies of the power output of an electric-arc heated gasdynamic laser (after-mixing-type) over a wide range of physical parameters near the mixing holes. When He gas was mixed, power output continued to increase with increasing flow rates of Co2 and He. On the other hand, without He, it showed saturation or decrease as the flow rate was increased beyond a cer-tain point. The effect of the boundary layer produced in a supersonic nozzle on the power output of the gasdynamic laser has also been estimated.