Effects of ion irradiation on the normal state and superconducting properties of NbN thin films

Journal Article · Mon Aug 01 00:00:00 EDT 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.38.2354· OSTI ID:7145040

Juang, J Y; Rudman, D A; Talvacchio, J; van Dover, R B

The effects of ion-beam-induced damage on the normal state and superconducting properties of NbN were investigated in both single crystal and polycrystalline thin films. Three sets of films were damaged by 200-keV Ar/sup +/ ions with dosages up to 5 x 10/sup 16/ ions/cm/sup 2/. The superconducting critical temperature (T/sub c/) of the single crystal films decreased by 20% at the highest ion dosage. Changes in the resistivity, T/sub c/, and critical field (and its slope at T/sub c/) suggest that T/sub c/ is suppressed by a reduction of the electron density of states at the Fermi energy due to the vacancies created by ion irradiation. The effects of ion damage are much less pronounced for the polycrystalline films. In situ grain growth was observed during the ambient temperature irradiation processes, which confirms the role of grain boundaries as a sink for ion-induced defects, hence minimizing the effects of irradiation in polycrystalline films.

• Research Organization: Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
• OSTI ID: 7145040
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Vol. 38:4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
NIOBIUM NITRIDES
PHYSICAL RADIATION EFFECTS
SUPERCONDUCTIVITY
ARGON IONS
CRITICAL FIELD
ENERGY-LEVEL DENSITY
FERMI LEVEL
GRAIN BOUNDARIES
ION COLLISIONS
KEV RANGE 100-1000
MONOCRYSTALS
POLYCRYSTALS
THIN FILMS
TRANSITION TEMPERATURE
VACANCIES
CHARGED PARTICLES
COLLISIONS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY LEVELS
ENERGY RANGE
FILMS
IONS
KEV RANGE
MAGNETIC FIELDS
MICROSTRUCTURE
NIOBIUM COMPOUNDS
NITRIDES
NITROGEN COMPOUNDS
PHYSICAL PROPERTIES
PNICTIDES
POINT DEFECTS
RADIATION EFFECTS
REFRACTORY METAL COMPOUNDS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
360206* - Ceramics
Cermets
& Refractories- Radiation Effects
656100 - Condensed Matter Physics- Superconductivity