Self-adjusted flux for the traveling solvent floating zone growth of YBaCuFeO5 crystal

A modified traveling solvent floating zone (TSFZ) technique was used to successfully grow a large size and high quality single crystal of multiferroic material YBaCuFeO 5 . This modified TSFZ growth uses a stoichiometric feed rod and pure copper oxide as the initial flux without prior knowledge of the complex phase diagram involving four elements, and the optimal flux for the growth of incongruently melt crystal is self-adjusted after a prolonged stable pulling. The wetting of the feed rod edge that often perturbs the molten zone stability was avoided by adding 2 wt% B 2 O 3 . The optimal flux concentration for the YBaCuFeO 5 growth can be extracted to be near YBaCuFeO 5 :CuO=13:87 in molar ratio. The crystal quality was confirmed by the satisfactory refinement of crystal structure of space group P 4 mm and the two consecutive anisotropic antiferromagnetic phase transitions near 455 K and 170 K.