Tri-axial orientation of twin-free powders of RE2Ba 4Cu7O15-σ (RE247, RE = Y, Dy, Ho, Er) was attempted by modulated rotating magnetic fields. The c-axis orientation was almost completely achieved for all the four RE247 compounds, whereas the degrees of in-plane orientation depended on RE element. Especially for Y247, the degrees of in-plane and c-axis orientation were determined to be ∼ 2.5° and < 2°, respectively, by the φ-scanning and rocking curve measurements. This excellent in-plane orientation is comparable or superior to those for coated conductors (∼ 4°) and melt-solidified bulks (∼ 8°) of REBa2Cu3O7-σ. Magnetic field dependence of Lotgering factors revealed that the degrees of in-plane orientation were sensitive to the applied magnetic field. The required magnetic field for the tri-axial orientation is determined by the in-plane magnetic anisotropy rather than the magnetic anisotropy between in-plane and out-of-plane directions.
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