Magnetic properties and superconducting-fluctuation diamagnetism above T sub c in Bi sub 2 minus x Pb sub x Sr sub 2 CaCu sub 2 O sub 8+. delta. ( x =0. 0, 0. 1, 0. 2, 0. 3, 0. 5) and
- Ames Laboratory-U.S. Department of Energy and Department of Physics, Iowa State University, Ames, Iowa 50011 (US)
The magnetic susceptibilities {chi}({ital T}) of the title compounds above and below {ital T}{sub {ital c}} are reported. For the Bi{sub 2{minus}{ital x}}Pb{sub {ital x}}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (Bi 2:2:1:2) system, optimization of the phase purity and superconducting properties is found between {ital x}=0.2 and 0.3. The {chi}({ital T}) data for these Bi 2:2:1:2 and for the two Bi 2:2:2:3 samples increase monotonically with temperature from {ital T}{sub {ital c}} up to at least 400 K, exhibiting strong negative curvature below {similar to}200 K. From theoretical fits to the data in the two-dimensional regime above {ital T}{sub {ital c}} using the static Lawrence-Doniach model as modified by Klemm, we conclude that the negative curvature in {chi}({ital T}) for each sample arises from superconducting-fluctuation diamagnetism (SFD). The data are thus consistent with a superconducting order parameter of {ital s}-wave symmetry. From the fits to the data, the Ginzburg-Landau coherence lengths in the CuO{sub 2} planes were obtained and found to be {xi}{sub {ital a}{ital b}}(0)=20.4(2) A for Bi 2:2:1:2 and 11.8(4) A for Bi 2:2:2:3. The value for Bi 2:2:1:2 is comparable to those calculated from upper critical magnetic-field data for this compound (23.5--27.1 A). Our {xi}{sub {ital a}{ital b}}(0) values for Bi 2:2:1:2 and Bi 2:2:2:3 are also comparable with that (13.6 A) found from our previous similar analysis of the SFD in YBa{sub 2}Cu{sub 3}O{sub 7}. The possible role of the bridging oxygens out of the CuO{sub 2} plane in Bi 2:2:2:3 and the influence of the dynamics in the fits to the SFD in the Bi-based compounds remain to be addressed.
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 5945284
- Journal Information:
- Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 43:1; ISSN 0163-1829; ISSN PRBMD
- Country of Publication:
- United States
- Language:
- English
Similar Records
Superconducting fluctuation diamagnetism above T sub c in YBa sub 1 Cu sub 3 O sub 7 , La sub 1. 8 Sr sub 0. 2 CuO sub 4 , and Bi sub 2 minus x Pb sub x Sr sub 2 CaCu sub 2 O sub 8+. delta
Two-dimensional fluctuations in the magnetization of Bi sub 2 Sr sub 2 Ca sub 2 Cu sub 3 O sub 10
Related Subjects
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
BISMUTH COMPOUNDS
BISMUTH OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
COHERENCE LENGTH
COPPER COMPOUNDS
COPPER OXIDES
CRYSTALS
DIAMAGNETISM
DIMENSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FLUCTUATIONS
GINZBURG-LANDAU THEORY
LEAD COMPOUNDS
LEAD OXIDES
LENGTH
LOW TEMPERATURE
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
MAGNETISM
MEDIUM TEMPERATURE
MEISSNER-OCHSENFELD EFFECT
ORDER PARAMETERS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POLYCRYSTALS
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTIVITY
TRANSITION ELEMENT COMPOUNDS
ULTRALOW TEMPERATURE
VARIATIONS
VERY LOW TEMPERATURE