TRANSVERSE SUSCEPTIBILITY AND FERROMAGNETIC-RESONANCE OF HI-8 METAL-EVAPORATED TAPE

Transverse susceptibility (TS) and ferromagnetic resonance absorption (FMR) are measured on commercially available metal-evaporated video tape manufactured by the continuous varying incidence method, so that the columns are inclined at an angle upsilon(int) with respect to the recording direction. Due to the demagnetization of the tape the magnetization vector is at an extrinsic inclination angle upsilon(ext) < upsilon(int) with respect to the recording direction, which is determined to be 24-degrees by analyzing angular remanence curves. The results of TS and FMR measurements on the dependence of the angle upsilon(N) between applied field and tape normal are symmetrical to upsilon(N) = upsilon(ext). In-plane TS measurements parallel and perpendicular to the recording direction lead to H(A) = 440 kA/m and an intrinsic inclination angle upsilon(int) = 44-degrees. Using these values, measured and calculated resonance field values H(res) are in good agreement except for 0-degrees < upsilon(N) < 50-degrees. The analysis of H(res) in the vicinity of upsilon(N) = 24-degrees leads to H(A) = 640 kA/m and upsilon(int) = 37-degrees. Thus, Stoner-Wohlfarth behavior with lower anisotropy field strength as determined perpendicular to the preferential axis of magnetization is suggested. In contrast to TS measurements, no results can be found that fit the resonance field value both parallel and perpendicular to the film normal.