Supercondacting properties of stabilized beryllium modification

A study has been made into the superconducting characteristics Tsub(k) and Hsub(k) of a beryllium modification ensuring superconduction at about 9 deg K and stabilized prior to annealing with additives of such metals as aluminium and magnesium. The stabilized beryllium modification is formed in layers obtained as a result of simultaneous condensation of beryllium and additive metal on a substrate cooled to the liquid helium temperature. These layers are examined after annealing at temperatures up to 400 deg K. Aluminium produces a more pronounced stabilizing action. Tsub(k) of the BeAl layer after annealing at a temperature of about 300 deg K is approximately equal to 9.5 deg K, while that of the BeMg layer, 6.5 deg K. Respectively, higher magnetic fields are also obtained in the case of the BeAl layer: Hsub(k) approximately 0.8x10sup(4)Tsub(k) (in the case of BeMg, Hsub(k) approximately 0.6x10sup(4)Tsub(k)). As can be inferred from electronographic studies, the stabilized BeAl layer is a mechanical mixture of highly disperse beryllium crystallites with a grain size of about 90 A and aluminium crystallites with a grain size of about 80 A. The conclusion that follows is that there is no specific increase in superconduction either due to metal or dielectric additives. Two possibilities are discussed as to an explanation of the nature of high Tsub(k): it may be due either to the amorphous phase, or to a considerable distortion of the crytical structure