RefDoc
Haut

Faire une nouvelle recherche
Make a new search
Lancer la recherche


Titre du document / Document title

Flux Pinning Optimization of MgB2 Bulk Samples Prepared Using High-Energy Ball Milling and Addition of TaB2

Auteur(s) / Author(s)

RODRIGUES Durval (1 2) ; JIANYI JIANG (3) ; YE ZHU (4) ; VOYLES Paul (4) ; LARBALESTIER David C. (3) ; HELLSTROM Eric E. (3) ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) Departamento de Engenharia de Materiais, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP 12600-970, BRESIL
(2) CNPq, BRESIL
(3) Applied Superconductivity Center, Department of Mechanical Engineering, and National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, ETATS-UNIS
(4) Department of Materials Science and Engineering, University of Wisconsin, Madison, WI 53706, ETATS-UNIS

Résumé / Abstract

MgB2 is considered to be an important conductor for applications. Optimizing flux pinning in these conductors can improve their critical currents. Doping can influence flux pinning efficiency and grain connectivity, and also affect the resistivity, upper critical field and critical temperature. This study was designed to attempt the doping of MgB2 on the Mg sites with metal-diborides using high-energy ball milling. MgB2 samples were prepared by milling pre-reacted MgB2 and TaB2 powders using a Spex 8000M mill with WC jars and balls in a nitrogen-filled glove box. The mixing concentration in (Mg1-xTax)B2 was up to x = 0.10. Samples were removed from the WC jars after milling times up to 4000 minutes and formed into pellets using cold isostatic pressing. The pellets were heat treated in a hot isostatic press (HIP) at 1000° C under a pressure of 30 kpsi for 24 hours. The influence that milling time and TaB2 addition had on the microstructure and the resulting superconducting properties of TaB2-added MgB2 is discussed. Improvement of Jc at high magnetic fields and of pinning could be obtained in milled samples with added TaB2. The sample with added 5at.%TaB2 and milled for 300 minutes showed values of Jc ~ 7 × 105 A/cm2 and Fp ~ 14 GN/m3 at 2 T, 4.2 K. The milled and TaB2-mixed samples showed higher values of μ0 Hirr than the unmilled-unmixed sample.

Revue / Journal Title

IEEE transactions on applied superconductivity    ISSN  1051-8223 

Source / Source

Congrès
ASC2008 Applied Superconductivity Conference, Chigaco, IL , ETATS-UNIS (17/08/2008)
2009, vol. 19 (3), no 3 (1104 p.)  [Document : 5 p.] (15 ref.), [Notes: Part 3 of 3 parts], pp. 2797-2801 [5 page(s) (article)]

Langue / Language

Anglais

Editeur / Publisher

Institute of Electrical and Electronics Engineers, New York, NY, ETATS-UNIS  (1991) (Revue)

Mots-clés anglais / English Keywords

High temperature superconductor

;

Magnetic field

;

High field

;

Microstructure

;

Hot pressing

;

Heat treatment

;

Isostatic pressing

;

Critical temperature

;

Critical field

;

Resistivity

;

Performance evaluation

;

Doping

;

Critical current

;

Machining

;

High energy

;

Optimization

;

Optimization method

;

Flux pinning

;

Mots-clés français / French Keywords

Supraconducteur haute température

;

Champ magnétique

;

Champ intense

;

Microstructure

;

Pressage chaud

;

Traitement thermique

;

Pressage isostatique

;

Température critique

;

Champ critique

;

Résistivité

;

Evaluation performance

;

Dopage

;

Courant critique

;

Usinage

;

Haute énergie

;

Optimisation

;

Méthode optimisation

;

Ancrage flux

;

Mots-clés espagnols / Spanish Keywords

Supraconductor alta temperatura

;

Campo magnético

;

Campo intenso

;

Microestructura

;

Prensado caliente

;

Tratamiento térmico

;

Prensado isostático

;

Temperatura crítica

;

Campo crítico

;

Resistividad

;

Evaluación prestación

;

Doping

;

Corriente crítica

;

Mecanizado

;

Alta energía

;

Optimización

;

Método optimización

;

Anclaje flujo

;

Mots-clés d'auteur / Author Keywords

Addition of diborides

;

high-energy ball milling

;

MgB2

;

microstructural and superconducting characterization

;

Localisation / Location

INIST-CNRS, Cote INIST : 22424, 35400017185134.0630

Nº notice refdoc (ud4) : 21986345



Faire une nouvelle recherche
Make a new search
Lancer la recherche
Bas