Synthesis under ambient pressure and tri-axial magnetic orientation in REBa2Cu4O8 (RE = Y, Sm, Eu, Gd, Dy, Ho, Er)

We report the rare-earth (RE)-dependent magnetization axes of REBa2Cu4O8, which was synthesized by a flux method under ambient pressure, using powder samples tri-axially oriented in a modulated rotating magnetic field of 10 T. By optimizing the growth temperature and cooling rate, RE124 crystals were successfully grown for RE = Y, Sm, Eu, Gd, Dy, Ho, and Er. From the X-ray diffraction measurement, the magnetically oriented directions were largely dependent on the type of RE ions of RE124. However, the tri-axial magnetic anisotropies of RE124 could be qualitatively understood in terms of the magnitude relation between the single-ion magnetic anisotropy of RE3+ ions and the magnetic anisotropy generated by the CuO2 plane and Cu–O chain. For the practical use of this magneto-scientific process, the control of magnetization axes and tri-axial magnetic anisotropies through crystallochemical control is indispensable.

► REBa2Cu4O8 (RE124) was synthesized by a flux method in ambient pressure for RE = Y, Sm, Eu, Gd, Dy, Ho and Er.
► Tri-axial orientation of RE124 was achieved in a modulated rotating magnetic field of 10 T.
► Orientation axes in RE124 depended on the type of RE.
► Magnetization axes were determined from magnetic anisotropies of Cu and RE ions.