Magnetotransport and superconductivity in dilute Fe alloys NbSe/sub 2/, TaSe/sub 2/, and TaS/sub 2/. [B up to 220 kG, 0 to 10 at. % Fe]
Single crystals of dilute iron alloys of the layer structures NbSe/sub 2/, TaSe/sub 2/, and TaS/sub 2/ have been studied using measurements of magnetoresistance and Hall effect in magnetic fields up to 220 kG. Iron concentrations in the range 0--10 at.% can induce spin-exchange scattering, metal-insulator transitions, or enhanced superconducting anisotropy depending on the phase of the crystal and the type of iron doping. Kondo-like resistance minima accompanied by negative magnetoresistance and anomalous Hall effects are observed in the 2H phase of Fe/sub x/TaSe/sub 2/ and Fe/sub x/NbSe/sub 2/. A ln H behavior at high fields and a ln T behavior at zero field or low fields have been fit to theoretical expressions and antiferromagnetic exchange constants on the order of -0.1 eV are obtained. Excess iron doping of 2H-TaS/sub 2/ produces enhanced superconductivity characterized by parameters similar to those observed for organic intercalation. The interlayer coupling strength is consistent with a tunneling model describing both the iron-doped material and the organic intercalates. Substitutional iron doping of TaS/sub 2/ and TaSe/sub 2/ stabilizes the 1T phase and produces a dramatic rise in resistivity at low temperature following at T/sup -..cap alpha../ power-law behavior.
- Research Organization:
- Department of Physics, University of Virginia, Charlottesville, Virginia 22901
- OSTI ID:
- 7230883
- Journal Information:
- Phys. Rev., B; (United States), Vol. 15:7
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
IRON ALLOYS
HALL EFFECT
MAGNETORESISTANCE
NIOBIUM SELENIDES
TANTALUM SELENIDES
TANTALUM SULFIDES
DILUTE ALLOYS
ELECTRIC CONDUCTIVITY
KONDO EFFECT
MAGNETIC FIELDS
MONOCRYSTALS
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
TUNNEL EFFECT
ALLOYS
CHALCOGENIDES
CRYSTALS
ELECTRICAL PROPERTIES
NIOBIUM COMPOUNDS
PHYSICAL PROPERTIES
SELENIDES
SELENIUM COMPOUNDS
SULFIDES
SULFUR COMPOUNDS
TANTALUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360104* - Metals & Alloys- Physical Properties
360603 - Materials- Properties
656102 - Solid State Physics- Superconductivity- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena- (-1987)