Preparation of ferrite single crystals by new floating zone technique

Single crystals of Ni ferrites and Ni-Zn ferrites having good uniformity were prepared by a new floating zone technique. In the preparation of the Ni-ferrite single crystal the initial molten zone was made from the material having a composition different from that of seed crystal. This made the composition of precipitate from molten zone the same as that of the seed, and the composition of crystal uniform throughout the entire body. In the apparatus a halogen lamp and the sample were placed, respectively, on the two focal points of a closed elliptical reflector. Under an oxygen pressure of 30 atm, the vaporization of ZnO and the precipitation of another phase in Ni-Zn ferrite single crystals can be almost eliminated.