Impurity effects on superconductivity and magnetism in heavy electron and high-transition-temperature copper oxide compounds

Miscellaneous · Fri Jan 01 00:00:00 EST 1988

OSTI ID:5946979

Dalichaouch, Y

The effects of impurities on the superconducting and magnetic properties of the heavy electron UBe{sub 13} and URu{sub 2}Si{sub 2} compounds and the high transition temperature YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} material were studied to get a better understanding of their exceptional superconducting and magnetic ground state properties. This investigation was carried out by means of low temperature ac magnetic susceptibility {chi}{sub ac}(T), upper critical magnetic field H{sub c2}(T), electrical resistivity {rho}(T), dc magnetic susceptibility {chi}(T), and specific heat C(T). The influence of pressure P on the superconducting transition temperature {Tc} has been determined for the (U{sub 1-x} Th{sub x}) Be{sub 13} system. The phase diagram of {Tc}({chi}) for P = 10 kbar shows two distinct regions of superconductivity. The temperature T dependence of the upper critical magnetic field H{sub c2} was subsequently measured for two compositions (x=0 and 0.029) of (U{sub 1-x} Th{sub x}) Be{sub 13} doped with various concentration of Gd. These results are consistent with singlet superconductivity in UBe{sub 13} and either strong spin orbit scattering or triplet spin pairing (U{sub 0.97} Th{sub 0.03}) Be{sub 13}. The moderately heavy electron compound URu{sub 2}Si{sub 2} exhibits a spin density wave transition at T{sub o} = 17.5 K followed by superconductivity at {Tc} < 1.5 K. The superconducting transition temperature {Tc} of Y{sub 1-x} Pr{sub x}Ba{sub 2}Cu{sub 3}O{sub 7-{delta}} (0 {le} x {le} 1) and Y{sub 1-x}Na{sub x}Ba{sub 2}Cu{sub 3}O{sub 7-{delta}} (0 {le} x {le} 0.5) systems decrease monotonically with concentration x.

• Research Organization: California Univ., San Diego, CA (USA)
• OSTI ID: 5946979
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BARIUM OXIDES
PHYSICAL PROPERTIES
BERYLLIUM ALLOYS
COPPER OXIDES
PRASEODYMIUM OXIDES
RUTHENIUM ALLOYS
SILICON ALLOYS
SODIUM OXIDES
URANIUM ALLOYS
YTTRIUM OXIDES
CRITICAL FIELD
ELECTRIC CONDUCTIVITY
IMPURITIES
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
PHASE DIAGRAMS
PRESSURE EFFECTS
SPECIFIC HEAT
SUPERCONDUCTIVITY
TRANSITION TEMPERATURE
ACTINIDE ALLOYS
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
DIAGRAMS
ELECTRICAL PROPERTIES
MAGNETIC FIELDS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METAL ALLOYS
PRASEODYMIUM COMPOUNDS
RARE EARTH COMPOUNDS
SODIUM COMPOUNDS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360104* - Metals &amp; Alloys- Physical Properties
360204 - Ceramics
Cermets
&amp; Refractories- Physical Properties
656100 - Condensed Matter Physics- Superconductivity