Abstract: A new method for preparation of Mn-Zn or Ni-Zn type ferrite single crystals. The ferrite materials are provided in a lower portion of a crucible and completely dissolved. The crucible is moved within a predetermined atmosphere of temperature gradient. A solid which is equilibrium in composition to the ferrite materials is supplied into the crucible while the dissolved ferrite materials are crystallizing from the lower extremity while a liquid-phase zone is maintained constant in depth. Ferrite single crystals of at least about 800 mm in length are grown which are homogeneous in composition throughout their length.

Abstract: A process for producing Ni-Mn-Zn ferrite single crystal for high frequency wherein a sample comprising 10-30 molar percent of NiO, 1.8-12 molar percent of MnO, 15-35 molar percent of ZnO and 49-53 molar percent of Fe.sub.2 O.sub.3 is melted and subjected to growing into a crystal under an oxygen partial pressure of below about 100 Kg/cm.sup.2.