Iwata Takao

On the A. C. Magnetization Characteristics of a Perminvar Wire

A. C. magnetization characteristics of a perminvar wire under tension were observed and discussed on the basis of the pipe-domain theory, the results of the discussion being compared with those based on the classical eddy current theory. It was found that the said domain theory would give a semi-quantitative interpretation of the a. e. data, and suggest the existence of an effect other than eddy currents. These results were, in essential, in agreement with the prediction by Williams and others on the a. c. magnetization characteristics of a single crystal of silicon iron. In connection with this, an account was given of an experiment based on the usual technique of estimation of the mean volume of domains and it was found that estimated sizes of the volume had little significance for the a. c. characteristics.