Effects of preparation conditions and low-temperature ion irradiation on superconductivity and electrical resistivity of amorphous (Mo/sub 0. 6/Ru/sub 0. 4/)/sub 1-x/B/sub x/ films

Journal Article · Tue Feb 01 04:00:00 EST 1983 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.332081· OSTI ID:6541235

Soeldner, L; Adrian, H; Bieger, J; Brenner, K; Noelscher, C; Saemann-Ischenko, G

Thin amorphous films of superconducting (Mo/sub 0.6/Ru/sub 0.4/)/sub 1-x/B/sub x/ were prepared by magnetron sputtering in an ultrahigh vacuum (UHV) system. The superconducting properties and normal state resistivities rho of films condensed at 77 K are discussed. We find a strong dependence on the sputter conditions of the low-temperature resistivity rho/sub L/T = rho (25 K) and its variation upon irradiation with 20-MeV sulphur ions, although the superconducting critical temperature T/sub c/ and the temperature dependence of rho are not strongly influenced for all films prepared. Whereas films sputtered with argon pressures below approx.10/sup -2/ mbar have resistivities of about 100 ..mu cap omega.. cm which are reduced 2--3% by irradiation, films sputtered with higher argon pressures have resistivities up to 1000 ..mu cap omega.. cm and show irradiation-induced decreases of almost 70%. Independent of this behavior, the x-ray diffraction patterns appear nearly identical, and T/sub c/ increases 6--10% with irradiation. Assuming that irradiation defects reduce the structural short-range order, the effects observed with low-resistance films could be explained by a smearing of the structure factor S(k) and an enhancement of the electronic density of states at the Fermi level N(E/sub F/). Our results suggest that the structure of high-resistance films has initially a reduced density which is increased by irradiation.

• Research Organization: Physikalisches Institut der Universitaet Erlangen-Nuernberg, Erwin-Rommel-Str. 1, D-8520 Erlangen, Federal Republic of Germany
• OSTI ID: 6541235
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 54:2; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
360106 -- Metals & Alloys-- Radiation Effects
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
AMORPHOUS STATE
BORON ALLOYS
CHARGED PARTICLES
DIMENSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON TUBES
ELECTRONIC EQUIPMENT
ENERGY RANGE
EQUIPMENT
FILMS
IONS
IRRADIATION
LOW TEMPERATURE
MAGNETRONS
MEDIUM VACUUM
MEV RANGE
MICROWAVE EQUIPMENT
MICROWAVE TUBES
MOLYBDENUM ALLOYS
PHYSICAL PROPERTIES
PHYSICAL RADIATION EFFECTS
PLATINUM METAL ALLOYS
PRESSURE DEPENDENCE
RADIATION EFFECTS
RUTHENIUM ALLOYS
SPUTTERING
SULFUR IONS
SUPERCONDUCTING FILMS
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
THICKNESS
TRANSITION TEMPERATURE
ULTRAHIGH VACUUM