Superconducting properties of ion-implanted gold-silicon thin films

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:5153612

Jisrawi, N M

The superconducting properties of thin Au{sub x}Si{sub 1{minus}x}, films prepared by ion beam implantation and ion beam mixing are studied. The films are prepared by evaporation of single Au layers on Si substrates and mixing them with Si, Ar, or Xe, or by Xe beam mixing of alternate multilayers of Au and Si sputtered on Al{sub 2}O{sub 3} substrates. The superconducting transition temperature and upper critical fields are determined by measuring the temperature and magnetic field dependence of resistivity. Temperatures as low as 20mK and magnetic fields as high as 8 T were used. Superconductivity in these films is discussed in connection with metastable metallic phases that are reportedly produced in the Au-Si system by high quenching rate preparation techniques like quenching from the vapor or the melt or ion implantation. Preliminary structural studies provide evidence for the existence of these phases and near-edge X-ray absorption and X-ray photoelectron spectroscopy measurements indicate a metallic type of bonding from which compound formation is inferred. The quality of the films is strongly dependent on the conditions of implantation. The maximum superconducting transition temperature attained is about 1.2 K. The upper critical fields have a maximum of 6T. An unusual double transition in the field dependence of resistivity is observed at low temperatures. The effect is very pronounced at compositions near x = 0.5 where the maximum {Tc} occurs. A model is presented to explain this result which invokes the properties of the metastable metallic phases and assumes the formation of more than two such phases in the same sample as the implantation dose increases. The Si-Au interface plays an important role in understanding the model and in interpreting the results of this thesis in general.

• Research Organization: Rutgers-the State Univ., New Brunswick, NJ (United States)
• OSTI ID: 5153612
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CERAMICS
SUPERCONDUCTIVITY
COMPOSITE MATERIALS
GOLD
SILICON
ALUMINIUM OXIDES
CRITICAL FIELD
HIGH-TC SUPERCONDUCTORS
INTERFACES
ION IMPLANTATION
MATHEMATICAL MODELS
SUBSTRATES
SUPERCONDUCTING COMPOSITES
SUPERCONDUCTING FILMS
TRANSITION TEMPERATURE
VERY LOW TEMPERATURE
ALUMINIUM COMPOUNDS
CHALCOGENIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
FILMS
MAGNETIC FIELDS
MATERIALS
METALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SEMIMETALS
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
360603* - Materials- Properties
360204 - Ceramics
Cermets
& Refractories- Physical Properties
656100 - Condensed Matter Physics- Superconductivity