High- superconducting ceramic samples of the form (x = 0.3, 0.5, 0.7, 0.9 and 1) are prepared in a closed quartz tube at C. The electrical resistance versus temperature is measured in the temperature range between 15 K and room temperature. The effect of magnetic field and applied electric current on the second stage of the transition is studied. It is found that the transition does not occur at a definite temperature but in a temperature range which may approach 50 K or even more. This is believed to be due to the very short coherence length ( Å) of HTSCs or to the random motion of the magnetic flux. The results obtained in our work can give some information about superconducting grains and weak superconducting boundaries.

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Austenitic stainless steels (ASS) have inadequate resistance to stress corrosion cracking (SCC). There are several ways to minimise the risk of SCC. One method is to increase the nickel content of the ASS. Electroless and electroplated costings were applied to ASS, Type 304, in order to produce a thin layer of nickel on its surface. Also during the present study, a SCC test was carried out at constant load in a tensile‐testing machine. The results showed that a thin layer of austenitic phase that had a high concentration of nickel and chromium was produced. This layer had good corrosion resistance compared to that of the base material and contained lower concentrations of Cr and Ni. The results obtained in these experiments reveal that austenitic steel to which the electroless coating process had been applied showed improved resistance to SCC, due to the presence of precipitates of the hard phase, Ni3P, which retarded localised breakdown of the oxide film.

Samples of Ni76P24 metallic glass alloy were prepared by the electroplating technique. Two types of surfactant material, namely triton-X 100 (non-ionic) and sodium loruyl sulphate (anionic) were used, each of which was added-at different concentrations-to the preparation bath. The X-ray diffractograms of the samples indicate that the addition of surfactants has changed the disorder in the system. The electrical resistivity, measured by the conventional four-probe technique in a temperature range from 300 K down to 18 K, is reduced. Also the temperature coefficient of resistivity is changed to a positive value instead of remaining nearly zero. Moreover, the thermal expansion coefficient decreases as the concentration of surfactant increases. The results of all the measurements indicate that the anionic surfactant has more influence on the enhancement of the crystalline behaviour of the system than the non-ionic one does.