The particle packing of MP tape media is explored by means of a new measure
ment technique. Utilizing a narrow gap length record head, the tape is eval
uated throughout its thickness with the use of an incremental DC erase meas
urement. A quantitative analysis of the medium noise spectra at different e
rase currents allows for the packing fluctuations at different depths into
the tape to be proportioned. The technique provides a method for evaluating
the interface between the magnetic recording layer and non-magnetic underl
ayer in dual-layer tape, and measurements indicate that interfacial roughne
ss at the magnetic coating backside in some dual-layer media is a major sou
rce of medium noise. (C) 2001 Elsevier Science B.V. All rights reserved.