Homogeneous and fairly largesized manganese-zinc ferrite single crystals, which are applicable to ferrite head in VTR, has been grown by the flame fusion method. The operation conditions of the flame fusion apparatus and the preparation of suitable powder by calcination of the manganese-zinc-iron oxalate are described. The flame fusion technique is feasible for the single crystal growth of ferrite by the use of particular raw powder, when the conditions for the growth are controlled properly.
X-ray microanalyser revealed that the distributions of manganese and zinc were homogeneous in the single crystal boule except the surface layer with the thickness of 0.5mm.
The dislocation density was determined by an etch-pit technique. The pit-density of annealed sample was about 4.5×104 per cm and about one-tenth times smaller than that of the as-grown sample. The magnetic and the electric properties of the single crystals are also described.
The output and the mechanical wear resistances of the ferrite head manufactured from the single crystal under investigation are dependent on the orientation of crystal axes in head construction.