1976 年 42 巻 494 号 p. 203-208
The magnetic properties of Mn-Zn single crystal ferrites which are used for VTR magnetic heads are very sensitive to machining. The machining processes are performed such as slicing, lapping and polishing on (110) and (100) planes of the toroid samples to investigate the effects on magnetization process. The frequency characteristics of initial permeability is measured to give the permeability dependency on degree of machining processes, such that the sliced toroid has higher permeability than the lapped one and gives rather comparable value with the polished toroid. The reduction of the sample thickness from 0. 5 mm to 0. 2 mm results in flattening the frequency characteristics. Comparison of the permeability of the etched toroid with that of the machined one gives the large permeability reduction in the low frequencies and the small reduction in high frequencies for the machined toroid, which suggests the magnetization of domain wall displacement would be disturbed by machining. The difference of permeability recovering curves due to etching among machining processes leads the idea that the changes of magnetization processes are different.