Surface structure of high-T/sub c/ Nb/sub 3/Ge films

Journal Article · Thu Apr 01 04:00:00 EST 1982 · J. Low Temp. Phys.; (United States)

DOI:https://doi.org/10.1007/BF00682022· OSTI ID:5557325

Kuriki, S; Ohora, T

We have studied the surface structure of rf-sputtered Nb/sub 3/Ge films by means of reflection electron diffraction and Auger electron spectroscopy. It is found that a tetragonal Nb/sub 5/Ge/sub 3/ phase exists, being partly disordered, at the surface of high-T/sub c/ films, whereas A15 phase is predominant in the body of the film as proved by x-ray diffraction. The tetragonal surface phase is replaced by an amorphous phase in thin films of <1000 A, where reduced T/sub c/'s as compared with those of thick films are found. Single A15 phase occurs at the surface of Ge-deficient films whch have low T/sub c/'s. Auger analysis has shown a pronounced Ge-rich layer with a depth of 60-100 A, depending on film composition and thickness. At the top of the surface layer, Ge is enriched beyond a composition corresponding to Nb/sub 5/Ge/sub 3/. It is inferred that the Ge-rich layer is responsible for formation of the tetragonal phase.

• Research Organization: Research Institute of Applied Electricity, Hokkaido University, Sapporo, Japan
• OSTI ID: 5557325
• Journal Information: J. Low Temp. Phys.; (United States), Journal Name: J. Low Temp. Phys.; (United States) Vol. 47:1; ISSN JLTPA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals &amp; Alloys-- Physical Properties
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
&amp; Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
AUGER ELECTRON SPECTROSCOPY
COHERENT SCATTERING
DATA
DIFFRACTION
ELECTRON DIFFRACTION
ELECTRON SPECTROSCOPY
EXPERIMENTAL DATA
FILMS
GERMANIUM ALLOYS
INFORMATION
LAYERS
NIOBIUM ALLOYS
NUMERICAL DATA
PHYSICAL PROPERTIES
QUANTITY RATIO
SCATTERING
SPECTROSCOPY
SUPERCONDUCTING FILMS
SURFACE PROPERTIES
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE