TY - JOUR
T1 - Critical current density-magnetic field curve for untwinned orthorhombic Nd1+xBa2-xCu3O7±δ single crystal and its microstructure
AU - Oka, Akihiro
AU - Koyama, Satoshi
AU - Izumi, Teruo
AU - Shiohara, Yuh
AU - Ma, Xiuliang
AU - Yamamoto, Takahisa
AU - Ikuhara, Yuichi
AU - Sakuma, Taketo
AU - Sugawara, Yoshihiro
AU - Hirayama, Tsukasa
PY - 2000/12/1
Y1 - 2000/12/1
N2 - Critical current density-magnetic field (Jc-H) curves with H ∥ c-axis for untwinned orthorhombic Nd1+xBa2-x.,Cu3O7±δ (Nd123, x = 0.07) single crystals were investigated. Untwinned single crystals were prepared by two different fabrication processes under uniaxial stress: a detwinning process and a twin-free process. The peak effects for twin-free crystals were larger than those for detwinned crystals. The results of evaluation of the Nd/Ba configurations in these single crystals by extended X-ray absorption fine structure (EXAFS) spectroscopy and transmission electron microscopy (TEM) suggested that a larger number of pinning centers of Nd-rich phases were distributed more finely in twin-free crystals, so that the peak effects in their JC-H curves increased. Furthermore, it is possible that the heat treatments under uniaxial stress affected the progress of Nd/Ba ratio fluctuation by means of the spinodal decomposition mechanism, which caused the fine distribution of Nd-rich phases in twin-free crystals. Nd123, JC-H curve, peak effect, EXAFS, TEM, spinodal decomposition
AB - Critical current density-magnetic field (Jc-H) curves with H ∥ c-axis for untwinned orthorhombic Nd1+xBa2-x.,Cu3O7±δ (Nd123, x = 0.07) single crystals were investigated. Untwinned single crystals were prepared by two different fabrication processes under uniaxial stress: a detwinning process and a twin-free process. The peak effects for twin-free crystals were larger than those for detwinned crystals. The results of evaluation of the Nd/Ba configurations in these single crystals by extended X-ray absorption fine structure (EXAFS) spectroscopy and transmission electron microscopy (TEM) suggested that a larger number of pinning centers of Nd-rich phases were distributed more finely in twin-free crystals, so that the peak effects in their JC-H curves increased. Furthermore, it is possible that the heat treatments under uniaxial stress affected the progress of Nd/Ba ratio fluctuation by means of the spinodal decomposition mechanism, which caused the fine distribution of Nd-rich phases in twin-free crystals. Nd123, JC-H curve, peak effect, EXAFS, TEM, spinodal decomposition
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U2 - 10.1143/jjap.39.6515
DO - 10.1143/jjap.39.6515
M3 - Article
AN - SCOPUS:15844364254
SN - 0021-4922
VL - 39
SP - 6515
EP - 6522
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
IS - 12 A
ER -