Prakt. Met. Sonderband 38 (2006) 511 
m aber bei MICROSTRUCTURE OF BaCeO; ADDED, MELT PROCESSED 
ICKE, diese 
ew Y-Ba-Cu-O SUPERCONDUCTOR 
- nach der 
dung von Chan-Joong Kim*, Hai-Woong Park**, Chung-Keun Kim** 
echanische 
isten. Zur 
Ingen zur *Nano-materials application laboratory, Korea Atomic Energy Research Institute, Daejeon, Korea 
rt. In den ** Advanced materials engineering department, Korea University of Technology and Education, 
;he höhere ch 
eonan, Korea 
1/Nb bzw. 
hen Werte 
verden die 
t. 
ABSTRACT 
Nano-size particle inclusion can act as a flux pinning center of Y-Ba-Cu-O superconductor. 
-cond. Sei 5-20 wt.% of BaCeO; solid particles were mixed with Y-Ba-Cu-O powders with and without 
a Y2BaCuOs using balling milling and the mixed powders were made into compacts. The 
Fuchs, G.: compacts were melt-processed following the conventional melting schedule including the 
supercond. peritectic reaction. The microstructures of the melt-processed samples were investigated 
wders and using optical microscope and scanning electron microscope. The particle distribution of 
chnol., 17, BaCeO; and Y;BaCuOs showed their typical segregation modes in the textured 
YBayCu307.4. The segregation mode of the inclusion particles was explained in term of the 
Eckert, J. lid particle motion ahead of th i tal i It 
s prepared solid particle motion ahead of the growing crystal in a melt. 
ubert, M., 
| alloying: 
1. Introduction 
A number of studies have been carried out for the microstructural modification of the 
YBa Cu307-x(Y123) superconductor because the current-carrying properties highly 
depend on the characteristics of its microstructure. The grain alignment of superconducting 
grains to the direction of current path increased critical current density(Jc) at high magnetic 
fields.[1,2] With the aligned microstructure, the addition of the second inclusion phase 
such as Y;BaCuOs5(Y211), BaCeO3 and PtO; into Y123 superconductor system is known 
to improve Jc further by increasing defect density near second particles, and/or refining the 
Y211 particles, which is considered to be a flux pinning medium for the Y123 phase. 
Although the mechanism for the high Jc due to the second phase addition is not yet clearly 
understood, the defects near the second phase particles or the interface between the 
second phase and the superconducting matrix is thought to contribute to the high Jc. The 
sharp interfaces between the fine Y211 particles and the Y123 matrix can be effective flux