Structural and physical properties of the metal (M) substituted YBa/sub 2/Cu/sub 3/. sqrt. /sub x/M/sub x/O/sub 7/. sqrt. /sub y/ perovskite
The mixed YBa/sub 2/Cu/sub 3/..sqrt../sub x/M/sub x/O/sub 7/..sqrt../sub y/ (M = Ni, Zn, Fe, Co, and Al) phases have been characterized for their structural, magnetic, and superconducting properties. The oxygen content in these phases is dependent on the nature and the amount of doping, especially for Co and Fe. The material remains orthorhombic when Cu is replaced by Ni or Zn whereas it evolves to tetragonal symmetry for the Fe-, Co-, and Al-doped compounds when x exceeds 0.05. Evidence for the major substitution of Co in the Cu-O chains only is obtained by means of thermogravimetric analysis and neutron diffraction measurements. The room-temperature Moessbauer spectra of the Fe-doped compounds consist of three doublets; their site assignments are proposed. dc resistance and ac susceptibility have shown that both magnetic and diamagnetic ions destroy T/sub c/ in a similar manner. At x = 0.2 the Fe and Co compounds are tetragonal, superconduct at 50 K, and show a Curie-type magnetic behavior associated with a magnetic moment of 3.4..mu../sub B/ per doping atom. The origin of the orthorhombic-tetragonal transition and the importance of the Cu-O chains for superconductivity is discussed. The behavior of these materials with respect to magnetic impurities is apparently different from conventional Bardeen-Cooper-Schrieffer-type superconductors, and we believe that any new mechanism proposed must be mostly sensitive to local structural disorder
- Research Organization:
- Bell Communications Research Inc., 331 Newman Springs Road, Red Bank, New Jersey 07701
- OSTI ID:
- 5221014
- Journal Information:
- Phys. Rev. B: Condens. Matter; (United States), Vol. 37:13
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BARIUM OXIDES
CRYSTAL STRUCTURE
IMPURITIES
MAGNETIC PROPERTIES
SUPERCONDUCTIVITY
COPPER OXIDES
YTTRIUM OXIDES
ALUMINIUM ADDITIONS
COBALT ADDITIONS
DOPED MATERIALS
IRON ADDITIONS
NICKEL ADDITIONS
PEROVSKITES
ZINC ADDITIONS
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
ALUMINIUM ALLOYS
BARIUM COMPOUNDS
CHALCOGENIDES
COBALT ALLOYS
COPPER COMPOUNDS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
IRON ALLOYS
MATERIALS
NICKEL ALLOYS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
ZINC ALLOYS
360204* - Ceramics
Cermets
& Refractories- Physical Properties
656100 - Condensed Matter Physics- Superconductivity