SIMULTANEOUS MEASUREMENT OF THE RESISTIVITY AND PERMEABILITY OF A FILM SAMPLE WITH A DOUBLE COIL

A method is proposed for a simultaneous measurement of the resistivity and permeability of a film inserted between two coils facing each oth er, Connecting in series, the total impedance of the coils was measure d in two ways, i.e., 1) the current passes through the coils in the sa me direction, and 2) the current passes through each coil in opposite directions to each other, The resistivity and permeability of the film were simultaneously obtained from the difference in the impedance for the two cases, It was theoretically found that the optimum frequency for high accuracy in the measurement was proportional to the resistivi ty and inversely proportional to a thickness of a sample film. The res ults of the simultaneous measurements of the resistivity and permeabil ity of nickel films of a thickness ranging from 0.01-0.08 mm at a freq uency range of 1-100 kHz are shown in this paper, The measured values of the resistivity and permeability with this;method agreed with the v alues obtained by conventional methods, i.e., the dc four-probe method for the resistivity measurement and the toroidal coil method for the permeability measurement.