Tl, Bi, and Pb doping in Ba[sub 4]BiPb[sub 2]TlO[sub 12-[delta]]

Journal Article · · Chemistry of Materials; (United States)

OSTI ID:5121645

Sutto, T E; Averill, B A ^[1]

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1. Univ. of Virginia, Charlottesville, VA (United States)

To determine the effects of different 6s metal concentrations on the superconducting nature of Ba[sub 4]BiPb[sub 2]TlO[sub 12[minus][delta]], materials produced via four doping schemes were examined: Ba[sub 4]Bi(Pb, Tl)[sub 3]O[sub 12[minus][delta]], Ba[sub 4][minus](BiPb)[sub 3]TlO[sub 12[minus][delta]], Ba[sub 4](Bi,Tl)[sub 2]Pb[sub 2]O[sub 12[minus][delta]], and Ba[sub 4]Bi[sub x]Pb[sub 4-2x]Tl[sub x]O[sub 12[minus][delta]]. For the parent compound a value of [delta] = 0.91 was observed, indicating that approximately 1/4 oxygen atom was missing per cubic subsection of the unit cell. For all samples, the symmetry of the parent compound changed from orthorhombic to tetragonal as the system moved away from the ideal composition. This was usually accompanied by the loss of superconductivity, which exhibited a maximum T[sub c] of 10.5 K for the parent compound Ba[sub 4]BiPb[sub 2]TlO[sub 12[minus][delta]]. Also reported are high-temperature magnetic susceptibility results, which are used to determine the effect of metal substitution on the density of states at the Fermi level. For each set of variants on the parent composition, the onset of superconductivity was accompanied by a significant decrease in the size of the Pauli paramagnetic signal. 16 refs., 6 figs.

• OSTI ID: 5121645
• Journal Information: Chemistry of Materials; (United States), Journal Name: Chemistry of Materials; (United States) Vol. 4:5; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BISMUTH COMPOUNDS
CHALCOGENIDES
CRYSTAL DOPING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
LEAD COMPOUNDS
ORTHORHOMBIC LATTICES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
STOICHIOMETRY
SUPERCONDUCTIVITY
TETRAGONAL LATTICES
THALLIUM COMPOUNDS