The image obtained through the high resolution electron microscope is described in a comprehensible form by means of phase contrast transfer function. Besides, the condition for imaging the crossed lattice of crystals and the electron beam holography of Fraunhofer type are explained theoretically and experimentally. The features and construction of the high voltage electron microscope are briefly described.
The blue and the green components of the thermoluminescence of ZnS: Cu, Al powder phosphor were recorded separately. Temperature for the blue peak was found to be about 120°K, and that for the green, about 140°K. With increased Al concentration (Cu concentration was constant), the emission spectrum changed from blue to green. The transition model of each spectrum and the nature of luminescence center are discussed.
Dependences of the sticking probability on the degree of vacuum and the substrate temperature in vacuum deposition of Nickel were investigated by use of a specially designed evaporation rate monitor and an improved Miller-type integrational operational amplifier. Quantities proportional to the sticking probability, average grain size and electrical conductivity of the deposited film were measured against the thickness of the film. They all showed similar cyclic curves with increasing film thickness. In observing the film under an electron microscope, the surface of high sticking probability was rough while that of low sticking probability was smooth. These results suggest that the sticking probability is closely correlated to the grain size of the deposited film.
Thin films of Ta, Nb and Pt are prepared on glass substrates by the cathode sputtering method in an atmosphere of argon. The sputtering is carried out at argon pressures of 3, 5 and 8×10-2 Torr. and at electrode distances, d, of 2.3, 3 and 4cm. The sputtered amount, Q0, from the cathode, is derived as a function of ion energy, which is related linearly to applied voltage V in the case of glow discharge at low pressure. In our experimental range, the deposited amount, Q, on the substrate, is proportional to the sputtered amount with the relation Q∝Q0/dn (n=0.5_??_2), and the effect of argon pressure on the deposited amount is hardly detectable. It is shown that according to our results, the deposited amount is proportional to V2.5 in the high energy region, and V4 in the low energy region.
The mean square fluctuations of log-amplitude and phase are analytically obtained for a gaussian light beam propagating through a randomly inhomogeneous medium with gaussian covariance of the refractive-index fluctuations. The beam used is radiated from an extended source with a circularly symmetric gaussian amplitude distribution and a curved wavefront (phase variation) which characterize the beam shape. The dependence of the fluctuation distribution upon the beam shape and the degree of turbulence in the medium is discussed.
Single crystals of p-type α silicon carbide were made from commercial grade silicon carbide with Al2O3 in a furnace of Lely's type. Major effort was paid to obtain the highly Al-doped crystals that enable us to prepare tunnel diodes, In the case of 13wt.% of Al2O3 concentration, no crystal could grow. Tunnel diodes could be made with the crystals made from raw material containing 6.5wt.% or greater concentration of Al2O3, by means of an alloy technique with silicon in an atmosphere of nitrogen and hydrogen. The characteristics of tunnel diodes were observed in the temperature range from 4.2°K to 523°K. Negative resistance was practically absent above 400°K.