The conduction processes in silicon nitride

The electrical conduction processes through silicon nitride are examined and discussed. Three processes were found to occur: Frenkel–Poole emission, field ionization, and trap hopping. The characteristic constant for the field ionization was found to be lower than expected (~5 × 106 V cm−1), and the thermal activation energy for the trap hopping was between 0.08 and 0.10 eV. The Frenkel–Poole effect indicated trap depths varying from 0.50 to 0.85 eV for various devices, and was more complicated than previously reported. All of the processes were bulk limited. Approximate values of m*/m and the mobility at 300 °K were found to be 0.20 and 0.13 cm2/V s respectively.

An experimental examination of the electrostatic behaviour of supraconductors.

In previous papers of F. and H. London supraconductivity has been described as a phenomenon, in which the current density is not connected with the electric field, as in normal conductors, but depends on magnetic field strength according to the equation Λ c curl J = - H with B = H and with Λ = m / ne 2, a new characteristic constant which contains the number n of supraconducting electrons. the behaviour of the electric field is not completely determined by this equation. Using Maxwell's induction law one can conclude from (1) only that Λ c curl j = c curl E or Λj = E + grand μ, where the physical signifance of grad μ is yet unknown.

SPONTANEOUS DECREASE OF THE SURFACE TENSION OF SERUM. I

1. Over 3,000 measurements of surface tension of sera have been made with the ring method, and they have yielded a new phenomenon, the spontaneous and rapid decrease of the surface tension of a serum in function of the time. 2. Generally, after 10 minutes the surface tension reaches a value which is practically constant. At least, the decrease is very much slower. After stirring, a rise occurs and a similar phenomenon takes place; but stability is not obtained as rapidly, requiring about 25 minutes. By stirring again, the same thing happens repeatedly, the slope of the curve being less marked each time, the rise in surface tension being slightly below each previous value, and the phenomenon undergoing a sort of damping. 3. An equation was established which expresses the experimental facts with an accuracy of about 0.2 per cent. It applies to the whole phenomenon, before and after stirring. It has only one characteristic constant, See PDF for Equation This formula, by simply changing t to c (concentration), expresses satisfactorily in general the phenomenon of adsorption in the surface layer; that is, the decrease in surface tension in function of the concentration. 4. Prolonged heat, at 55°C., and time seem to inhibit this phenomenon. 5. When precipitation occurs in a serum, the bottom of the liquid, which contains the precipitate, has the highest surface tension. When stirred, the surface tension rises a little every time. The upper part, clear, with lower surface tension, shows the reverse phenomenon; after every stirring, the surface tension becomes a little lower.