Superconducting properties of amorphous MoX (X = Si, Ge) alloy films for Abrikosov vortex memory

Journal Article · Tue Mar 15 04:00:00 EST 1988 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.341105· OSTI ID:5418958

Kubo, S

Structural and superconducting properties of amorphous MoSi (approx.55%Si) and MoGe (approx.30% Ge) films (200 and 50 nm in thickness) prepared by rf magnetron sputtering were examined for the purpose of application to Abrikosov vortex memory devices. Amorphous single-phase films were obtained at concentrations of 20% Si and above, while a crystalline phase was detected even at a concentration of 30% Ge. The highest critical temperature T/sub c/ was 7.2--7.3 K in Mo-20% Si films. Magnetic penetration depth lambda at 4.2 K and upper critical field dependence on temperature B/sub c//sub 2/(T) were measured. The B/sub c//sub 2/(T) behavior in the vicinity of T/sub c/ showed a tail-like shape, which most likely is the result of structural inhomogeneities in the prepared films. The lambda dependence on Si concentration was satisfactorily explained through the Ginzburg--Landau--Abrikosov--Gorkov (GLAG) dirty limit theory using the corrected critical temperature T/sup *//sub c/ which is defined by the B/sub c//sub 2/(T) results. Other superconducting parameters (GL parameter kappa/sub GL/ and coherence length xi/sub GL/ ) and bare electronic density of states N(0) were derived from the GLAG relationships using the temperature slope of B/sub c//sub 2/(T). Flux pinning was examined through the critical current measurements at 4.2 K in the perpendicular applied field to the film surface. Preliminary results on edge pinning estimation were also presented.

• Research Organization: NTT Opto-Electronics Laboratories, Tokai, Ibaraki 319-11, Japan
• OSTI ID: 5418958
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 63:6; ISSN JAPIA
• 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
DATA
EXPERIMENTAL DATA
FILMS
GERMANIUM ALLOYS
INFORMATION
MEMORY DEVICES
MOLYBDENUM ALLOYS
NUMERICAL DATA
PENETRATION DEPTH
PHYSICAL PROPERTIES
SILICON ALLOYS
SUPERCONDUCTING FILMS
THERMODYNAMIC PROPERTIES
THIN FILMS
TRANSITION TEMPERATURE