Microscopic investigation of NbN sputtered films

Conference · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5425286

Gray, K E; Kampwirth, R T; Capone, II, D W; Vaglio, R

Many favorable properties of niobium nitride (NbN) sputtered films for high field magnets are significantly less favorable in bulk NbN (and other high-field superconductors) so that differences in the microstructure of sputtered NbN films are likely responsible for the improvements. Very thin transverse sections of sputtered films were studied by TEM. Such studies reveal columnar grains. We report tunneling measurements that directly investigate T/sub c/ and the energy gap of individual grains. By placing electrodes above and below the film, preliminary measurements of the intrinsic resistivity of the individual columnar grains indicate values significantly less than the transport value. Measurements of the critical current density, J/sub c/, in NbN suggest that shearing of the flux line lattice does not limit J/sub c/, as in A-15 superconductors, no doubt due to the high density of pinning centers in NbN.

• Research Organization: Argonne National Lab., IL (USA)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5425286
• Report Number(s): CONF-8505138-11; ON: DE85015000
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRITICAL CURRENT
CURRENT DENSITY
CURRENTS
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
ENERGY GAP
FILMS
MICROSCOPY
NIOBIUM COMPOUNDS
NIOBIUM NITRIDES
NITRIDES
NITROGEN COMPOUNDS
PHYSICAL PROPERTIES
PNICTIDES
REFRACTORY METAL COMPOUNDS
SPUTTERING
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
TRANSMISSION ELECTRON MICROSCOPY