Measurement of Young\u27s Modulus with Small Stress

A modification of the apparatus previously described by Van Allen has been designed and used for measurements on zinc and lead crystals

Plasticity of Zinc Single Crystals

Some observations are presented of the plastic flow of zinc at very small stresses, just beyond the elastic limit

A Simple Method of Determining Horizontal Intensity of the Earth\u27s Magnetic Field

This method of determining the horizontal intensity of the earth\u27s magnetic field depends on well-known principles, which, however, do not seem to have been applied in exactly this fashion before. A magnet is suspended in a horizontal plane and allowed to vibrate under the joint influence of the earth\u27s field and a known controlling field in the same direction and in either the same or opposite sense. The controlling field is that of two similar circular coils placed a distance apart equal to the radius (arrangement of Gaugain and Helmholtz)

Effect of Additions of Cadmium on Growth of Zinc Crystals

Using the Czochralski-Gomperz method and various specimens of zinc containing certainly less than 1 per cent Cd., Schilling encountered mosaic crystals and failed to find the region of successful growth of Hoyem and Tyndall. It has been found, however, that by using zinc containing several tenths of one per cent of Cadmium the mosaics are largely prevented and a region of growth similar to the previous one reappears

Magnetization of Electrolytic Nickel Films

The magnetic properties of nickel films electrolytically deposited on brass tubes are determined by the method previously described for Iron and Cobalt films (Phys. Rev. 30, 681 (1927); 35 292 (1930). Films about 130 rnμ thick attain a magnetization of about 380 c. g. s. units in a field of 200 gauss, a value about equal to that for bulk nickel. As in Iron and Cobalt the coercive force is high, but the remanence is somewhat less than was found for iron and cobalt

Resistivity of Zinc Crystals

The resistivity at 20°C of zinc crystals made of Kahlbaum\u27s purest and of Spectroscopically Pure zinc (from New. Jersey Zinc Company) is given as a function of direction of current flow relative to the orientation of the crystal lattice. For the Kahlbaum crystals the results are very much more consistent than have previously been obtained and point to a higher ratio of p11/p1 than that obtained by Bridgman. The Spectroscopically Pure crystals agree in the main with the Kahlbaum, but there are a few exceptional cases which tend to confirm Bridgman\u27s strain theory. It seems more probable, however, that an explanation can be given in terms of the conditions governing the growth of the crystals

Mosaic Zinc Crystals

Crystals of a distinctly mosaic type (that is, a group of polycrystals with almost identical orientations) have been grown with great frequency during the last two years. Some types of these will be described and their bearing on the growth of single crystals by various methods will be discussed

Magnetic Properties of Thin Cobalt Films Electrolytically Deposited

Initial magnetization curves and hysteresis loops of cobalt films from 40 to 100 millimicrons thick show the same general characteristics as iron films of the same range of thickness. The specific properties, however, are largely dependent on the acidity of the electrolyte. The linear relation between thickness and reciprocal of coercive force discovered for iron films is not in general true for cobalt, though it is approximated in some series of films

Hysteresis in Zinc Crystals

Hanson found that crystals under bending stress showed a small amount of elastic hysteresis. It appears now that this hysteresis is characteristic of the apparatus used by Hanson, since a slight modification abolishes this hysteresis

Magnetization of Thin Films of Electrolytic Iron

The films of iron are preformed by electrolysis of a three per cent solution of ferrous ammonium sulfate and deposited on a brass cathode. The magnetic properties are similar to those of evaporated films (Sorenson, Edwards), a large increase in coercive force occurring at a thickness of about 50 millimicrons. This effect for electrolytic iron has heretofore been attributed to the occlusion of hydrogen, but the present work makes this hypothesis appear exceedingly unlikel