ZHANG Cheng
,
WANG Yongzhong
,
JIANG Ming
,
ZENG Dechang
,
TANG Hong
,
LI Zhongrun
,
QIAO Guiwen
,
CHUANG Yuzhi(Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang
,
ChinaManuscript received on 20 April 1995)
金属学报(英文版)
Bi-2212 superconductive oxides with nanometer grains have been prepared by means of crystallization from amorphous materials.The structure and grain-size of samples were examined by.X-ray.diffraction,scanning electron microscopy.and high resolution electron microscopy.The temperature dependence of the resistivity.and a.c.susceptibility was measured by the standard four-probe method and the standard mutual-induction measurement,respectively.With the decrease of temperature,the resistivity of the Bi-2212 phase with grain size in nanometer was found to diminish to zero without sudden drop.No diamagnetic transition was detected from room temperature to 4.2 K.The formation of the nanocrystalline 2212 phase and the effect of grain size on the superconductivity were discussed.
关键词:
:Bi-2212
,
null
,
null
,
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TANG Hong
,
XIANYU Ze
,
HU Qianli
,
QIAO Guiwen
,
WANG Yongzhong
,
ZHUANG Yuzhi1 1) Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang
,
China 2) Northeastern University
,
Shenyang
,
China Manuscript Received 7 March 1995
金属学报(英文版)
In this study, high-Tc YBaCuO superconductors with high Jc value were prepared using MTG(melting-textured growth) method. These superconductors with high density have Jc value in excess of 1.6×104 A/cm2 (77K, zero field) determined by using a d.c. standard four terminal method with the criterion of lμV/cm. The XRD and fractograph analysis revealed that the texture existed in whole MTG-processed YBaCuO sample which consists of the layered and plate-like grains of matrix phase YBa2Cu3Oy unidirectionally aligned along its (103) planes. The experimental results indicated that the connectivity between superconducting grains has been improved greatly and the weak-link problem has been overcome essentially.
关键词:
: YBaCuO high-Tc superconductor
,
null
,
null
,
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