The advantages of the thin magnetic layer of a metal particulate tape

A very thin and smooth magnetic coating of metal particulate (MP) tape is made possible by the dual coating method. This MP tape consists of a magnetic upper layer and a nonmagnetic underlayer composed of very fine (TiO₂) powder. The anticipated advantages of decreasing the thickness of the magnetic layer were observed. The Hc, Hr, and squareness increased as the thickness of the magnetic layer decreased. Thinning the layer to thicknesses below 0.3 μm increased the reproduced output by 1.5 dB and achieved the same value as the Hi-8 metal evaporated (ME) tape. The loss of the magnetic moment density under conditions of 60°C 90% RH is independent of the thickness of the magnetic layer. Although the thickness of this thin MP layer was the same as that of the HI-8 ME, the electromagnetic characteristics were different from those of the ME