Niobium superconducting bridges having a variable-thickness geometry consisting of a thin narrow implanted region joining two much thicker bulk films have been fabricated. The temperature dependence of the critical current is described well by the static theory of Likharev and Yakobson. The direct current and alternate current Josephson effects were observed at temperatures above the transition temperature T′c of the bridge. The magnetic field period of the ’’diffraction pattern’’ dependence on magnetic field is analyzed taking into account demagnetizing effects in an approximate way. This field period Hp is found as a function of the bridge width w and the length L for wide bridges (w/L≫1), i.e., Hp= (Φ0/μ0)/ 22/3w5/3L1/3.

Good Ohmic contacts to P−doped and undoped p−type CdTe have been obtained by evaporating Au or Pt on the surfaces in high vacuum (p<1×10−6 Torr) and firing these in a H2 atmosphere. This contact has been used on the crystals having carrier concentrations between 3×1014 and 3×1017 cm−3 and stayed nearly Ohmic down to 4 °K. Consequently, temperature dependences of Hall coefficients and resistivities have been measured and an impurity conduction has been found in the P−doped CdTe.

An adaptation of the Monch and Galster specimen form to the biaxial tensile testing of paper is described. This form gives a known, uniform, biaxial stress field. A versatile test instrument for use with such specimens, as well as with wet or dry uniaxial ones, is also described. Poisson's ratio values of well-bonded, isotropic handsheets measured in the elastic region with this equipment are closer to the expected value of approximately one-third than earlier measurements made on equipment using other specimen shapes. Good agreement is observed among Poisson's ratio measurements made biaxially and those made uniaxially on the same specimens. Also, agreement is reasonable with measurements made with an ultrasonic technique.

Very high-resistivity (I 01l_10 12 n em at 300 OK) layers have been obtained by AI vapor diffusion into ZnTe using iodine as a carrier gas under a Zn atmosphere without surface erosion. Avalanching MIS electroluminescent diodes were fabricated using this technique. Spectral outputs of the diodes are yellow at 300 oK and green or yellow-green at 77 oK. The external quantum efficiencies are 0.1 '" 0.2% in the yellow, 10% in the green, and 20% in the yellow-green. The yellow and the green electroluminescence appear to be due to an acceptor-donor pair consisting of the doubly ionizable Zn vacancy and an unknown donor, whereas the yellow-green is characteristic of AI-doped ZnTe.

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