Accession Number:

ADA142541

Title:

Thin Film Synthesis of Superconducting Chemical Compounds

Descriptive Note:

Final rept. 1 Jan 1981-30 Dec 1983

Corporate Author:

CORNELL UNIV ITHACA NY DEPT OF CHEMISTRY

Report Date:

1984-05-31

Pagination or Media Count:

15.0

Abstract:

The objective of this research was to define the chemical factors that affect onset of superconductivity in ternary compounds to determine how small changes in stoichiometry and microstructure influence critical temperature, how the number and placing of magnetic ions act to quench superconductivity, and how the crystal structure can be modified to enhance superconductivity. The approach was to synthesize, from ultrapure starting elements, ternary borides, silicides, sulfides and selenides of the second and third row transition elements, to characterize the new compounds for x-ray structure, electric and magnetic behavior, and then compare them with doped materials. Four kinds of compounds were investigated rare earth diosmium disilicides, rare earth osmium-iridium borides, layered structure transition metal dichalcogenides, and Chevrel type molybdenum ternaries. Both the rare earth osmium-iridium borides and rare earth diosmium disilicides were synthesized by arc melting. The crystal structures were refined and magnetic susceptibility studies revealed conventional Hunds rule behavior in the disilicides while the Pr, Nd Os, Ir 4B4 compounds are characterized by Van Vleck paramagnetism of closely spaced multiplets. Only La0s2Si2 and Lu0s2Si2 compounds are superconducting with Tcs in the 2-4K range. In the layered compounds, lithium intercalated ZrS2, ZrSe2, NbS2, and NbSe2 were studied.

Subject Categories:

  • Physical Chemistry
  • Electrical and Electronic Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE