Relationship between degrees of orientation and rotating speed in magnetically tri-axial-oriented RE-Ba-Cu-O superconductors

We report an effect of rotation speed (Ω) on the degrees of orientation of three different crystallographic axes for Y2Ba4Cu7Oy powders oriented under modulated rotation magnetic fields (MRFs) of 10 T. The degrees of inplane and c-axis orientations below 4° were achieved for the MRFs with Ω ≥ 10 rpm in 10 T. The hard magnetic axis, the b-axis, of Y247 was highly oriented even for the lowest rotation speed, Ω = 1 rpm, within the present study. However, the degrees of orientations of the first and secondary easy axes, were drastically reduced for Ω < 10 rpm. The present study revealed that, under the MRF of 10 T, the decrease in Ω induced the following of the first easy axis synchronized with by the rotation of magnetic fields, and gives us important information for the fabrication of triaxially oriented RE-based cuprate superconductors by the magneto-scientific process using MRF.