Title :
Stress induced change in hole concentration in superlattice films of bismuth-based oxide superconductors
Author :
Hatano, T. ; Labat, S. ; Ishii, A. ; Arisawa, S. ; Togano, K.
Author_Institution :
Nat. Res. Inst. for Metals, Ibaraki, Japan
fDate :
6/1/1999 12:00:00 AM
Abstract :
Superlattice films of bismuth-based oxide superconductors, for instance (2234)/sub 1/(2212)/sub 1/ and (2245)/sub 1/(2201)/sub 1/, have been synthesized by sequential sputter deposition of bismuth oxide, strontium-copper-oxide and calcium-copper-oxide monolayers. Crystal structures, superconducting transition temperatures and hole concentration of the films were studied by X-ray diffraction, Meissner effect and Hall effect measurements. It was observed that the superconducting transition temperatures were enhanced by forming superlattice films of overdoped (2212, 2201) and underdoped (2234, 2245) phases. The results can be understood by stress induced changes in the hole concentration between the overdoped and the underdoped phases originating from the epitaxial (lattice matching) formation of the superlattice films.
Keywords :
Hall effect; Meissner effect; X-ray diffraction; bismuth compounds; calcium compounds; crystal structure; high-temperature superconductors; internal stresses; sputter deposition; strontium compounds; superconducting superlattices; superconducting thin films; superconducting transition temperature; Bi-based oxide superconductors; BiSrCaCuO; Hall effect; Meissner effect; X-ray diffraction; crystal structure; epitaxial formation; hole concentration; lattice matching; overdoped phases; sequential sputter deposition; stress induced hole concentration changes; superconducting transition temperature; superlattice films; underdoped phases; Bismuth; Hall effect; Sputtering; Stress; Strontium compounds; Superconducting films; Superconducting transition temperature; Superconductivity; Superlattices; X-ray diffraction;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
