Magnetization studies of irradiation modified single crystal Y sub 1 Ba sub 2 Cu sub 3 O sub 7 superconductors: Flux creep and annealing effects

Conference · Tue Jan 01 00:00:00 EST 1991

OSTI ID:5239122

Thompson, J R ^[1]; Yang, Ren Sun ^[2]; Christen, D K; Kerchner, H R ^[3]; Malozemoff, A P; Civale, L; Marwick, A D; Worthington, T K; Krusin-Elbaum, L; Holtzberg, F ^[4]

---

1. Oak Ridge National Lab., TN (United States) Tennessee Univ., Knoxville, TN (United States). Dept. of Physics
2. Tennessee Univ., Knoxville, TN (United States). Dept. of Physics
3. Oak Ridge National Lab., TN (United States)
4. International Busine

Measurements of the static magnetization of a superconductor provide an informative and facile method to understand many of its properties. The objective of this paper is to analyze several features of the high temperature superconductor Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7}, hereafter referred to as YBCO. Of particular interest are the critical current density, which is related to irreversibility in the magnetization, and the effects of different types of defects in the material. These defects tend to pin'' or immobilize the quantized magnetic field lines (vortices) that permeate a Type-2 superconductor when it is immersed in a magnetic field H that is greater than the lower critical field H{sub cl}. This process is dramatically affected by the presence of giant flux creep,'' a pervasive feature of high temperature superconductors. In this work, high quality single crystals of Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7}, with {Tc} values >90 K, were studied in three forms: (1) as synthesized, with relatively low critical current density J{sub c}; (2) after irradiation with light ions (protons with 3 MeV energy), that created point defects and increased J{sub c} considerably; and (3) after irradiation with heavy ions (Sn-ions with 580 MeV energy) that created linear pinning defects parallel to the ion paths. We discuss first the irreversible vortex-state magnetization, the related critical current density J{sub c}, relaxation of the magnetization with time ( flux creep''), the dependence of pinning energy on the magnitude of current density J, long-term studies of magnetic relaxation and their relation to collective pinning models, and finally treat flux creep annealing'' experiments. Where possible, we compare and contrast the results achieved with point-like and linear flux pinning geometries. 31 refs., 17 figs.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5239122
• Report Number(s): CONF-910860-2; ON: DE91018858
• Resource Relation: Conference: NATO Advanced Study Institute on physics and materials science of high-temperature superconductors, Corfu Island (Greece), 18-31 Aug 1991
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BARIUM OXIDES
CRITICAL CURRENT
COPPER OXIDES
YTTRIUM OXIDES
ANNEALING
CRYSTAL DEFECTS
CRYSTALS
CURRENT DENSITY
HIGH-TC SUPERCONDUCTORS
IRRADIATION
MAGNETIZATION
PHYSICAL RADIATION EFFECTS
TIN IONS
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
CHARGED PARTICLES
COPPER COMPOUNDS
CRYSTAL STRUCTURE
CURRENTS
ELECTRIC CURRENTS
HEAT TREATMENTS
IONS
OXIDES
OXYGEN COMPOUNDS
RADIATION EFFECTS
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties
360206 - Ceramics
Cermets
& Refractories- Radiation Effects
656100 - Condensed Matter Physics- Superconductivity