Influence of radiation-induced disordering on the superconducting transition temperature of Nb/sub 3/Ir films

Journal Article · Thu Jan 01 04:00:00 EST 1987 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.35.55· OSTI ID:7155669

Schneider, R; Linker, G; Meyer, O

Evaporated single-phase A15 Nb/sub 3/Ir films were irradiated at room temperature with protons and helium ions to study the influence of the induced defect structures determined by x-ray diffraction measurements on the superconducting transition temperature T/sub c/. A reduction in T/sub c/ from 2.1 to 1.8 K was observed for energies deposited into nuclear collisions below 1 eV/atom. Beyond this threshold T/sub c/ increased and revealed values above the initial transition temperature of the unirradiated films depending on the irradiation conditions: 2.8 K for proton and 3.7 K for helium-ion irradiation. The changes in T/sub c/ were accompanied by a decrease of the Bragg-Williams long-range order parameter, a defect structure consisting of static displacements of the lattice atoms with average rms amplitudes in the range of 0.005 to 0.009 nm, and by partial amorphization. The maximum T/sub c/ value of 5.7 K was determined in totally amorphized films. Both the depressions and enhancements in T/sub c/ can be explained by changes of the electronic density of states at the Fermi energy due to smearing effects.

• Research Organization: Institut fuer Nukleare Festkoerperphysik, Kernforschungszentrum Karlsruhe G.m.b.H., Postfach 3640, D-7500 Karlsruhe 1, Federal Republic of Germany
• OSTI ID: 7155669
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 35:1; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
BARYONS
BETA-W LATTICES
CHARGED PARTICLES
COHERENT SCATTERING
COLLISIONS
CRYSTAL DEFECTS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALS
DATA
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONIC STRUCTURE
ELEMENTARY PARTICLES
ENERGY LEVELS
ENERGY-LEVEL DENSITY
EXPERIMENTAL DATA
FERMI LEVEL
FERMIONS
FILMS
HADRONS
HELIUM IONS
INFORMATION
ION COLLISIONS
IONS
IRIDIUM ALLOYS
MEDIUM TEMPERATURE
NIOBIUM ALLOYS
NUCLEONS
NUMERICAL DATA
ORDER PARAMETERS
PHYSICAL PROPERTIES
PHYSICAL RADIATION EFFECTS
PLATINUM METAL ALLOYS
POLYCRYSTALS
PROTONS
RADIATION EFFECTS
SCATTERING
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
ULTRAHIGH VACUUM
ULTRALOW TEMPERATURE
X-RAY DIFFRACTION