Experimental analysis of the effects of tape thickness on magnetic recording

Abstract

Advances in magnetic tape recording have produced media with magnetic layers as thin as 0.1 μm. In this article, a metal particulate tape with a magnetic layer thickness of ∼0.37 μm is compared to a standard thick media tape with a magnetic layer thickness of ∼4 μm. Measurements of the isolated pulse are made and shown to compare well with micromagnetic simulations. The replay voltage versus current is measured with a 4 μm track width, shielded magnetoresistive head at various densities. The thin tape shows better high density response at high currents than the thick tape. The simulations show that the transitions are sharper on the thin tape due to both the reduction in thickness, and an improvement in the particle orientation. The better oriented particles yield narrower pulses, thereby improving the high frequency response of the tape. Frequency response measurements are also taken with the magnetoresistive head, which yield a signal to noise ratio of ≳20 dB at 200 kfci. Last, overwrite performance versus current is compared for the two tapes plus a metal-evaporated (ME) tape with a 0.2 μm thick layer. A significant improvement in overwrite is seen on the ME tape.