Thin film synthesis of superconducting chemical compounds. Final report 1 January 1981-30 December 1983
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 Hund's rule behavior in the disilicides while the (Pr, Nd) (Os, Ir) 4B4 compounds are characterized by Van Vleck paramagnetism of closely spaced multiplets. Only LaOs/sub 2/Si/sub 2/ and LuOs/sub 2/Si/sub 2/ compounds are superconducting with Tc's in the 2-4K range. In the layered compounds, lithium intercalated ZrS/sub 2/, ZrSe/sub 2/, NbS/sub 2/, and NbSe/sub 2/ were studied.
- Research Organization:
- Cornell Univ., Ithaca, NY (USA). Dept. of Chemistry
- OSTI ID:
- 6367617
- Report Number(s):
- AD-A-142541/2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTORS
SYNTHESIS
BORIDES
CRITICAL TEMPERATURE
CRYSTAL STRUCTURE
ELECTRICAL PROPERTIES
LAYERS
MAGNETIC PROPERTIES
MICROSTRUCTURE
PARAMAGNETISM
SELENIDES
STOICHIOMETRY
SULFIDES
SUPERCONDUCTIVITY
THIN FILMS
BORON COMPOUNDS
CHALCOGENIDES
ELECTRIC CONDUCTIVITY
FILMS
MAGNETISM
PHYSICAL PROPERTIES
SELENIUM COMPOUNDS
SULFUR COMPOUNDS
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
360601* - Other Materials- Preparation & Manufacture