Study on Secondary Gap in Sendust MIG Heads

Sendust MIG heads were constructed with an oxide or noble metal layer deposited at the interface between the Sendust film and the ferrite. AES studies indicated that the deposition of barrier films such as Ir, Pt and SiO2 prevents the thermal diffusion of oxygen and hence oxidation of the Sendust film at the interface. The intensities of the (110) X-ray diffraction peak from initial Sendust layers deposited on a barrier film over MnZn ferrite were larger than for Sendust layers deposited directly on the MnZn ferrite. As a consequence, a MIG head constructed with Ir or SiO2 film between the Sendust film and the MnZn ferrite had a greatly reduced secondary gap effect.