A. Roesler et Jg. Zhu, Novel magnetic characterization of the head-medium interface in metal particle tape systems, IEEE MAGNET, 37(5), 2001, pp. 3850-3859
The head-medium noise of modern metal particle tape systems, which results
from spacing fluctuations during the recording of data, dominates the mediu
m noise of today's advanced digital tape. Traditionally, characterization o
f the head-medium interface has been performed by using interferometry or a
tomic force microscopy (AFM) measurements of the tape surface roughness. Ho
wever, surface roughness measurements on two advanced metal particle (MP) t
ape media displayed no correlation with the tape medium noise characteristi
cs. A new insight into the impact of the tape load-bearing surface distribu
tion on the head-tape spacing variation explained the shortcomings of the r
oughness measurements to gauge the medium noise. Assessing the performance
and characteristics of the head-medium interface requires a new methodology
. To satisfy this need, a novel magnetic recording measurement is presented
that offers a direct and complete characterization of the head-medium inte
rface. Measured data show excellent correlation with the noise power spectr
al density of square-wave recordings for several tape media. In addition, t
he measurement revealed that long wavelength components dominate the MP tap
e head-medium noise, resulting in a decrease of the playback broad-band noi
se voltage power for recordings with shorter wavelength. The measurement te
chnique provides new insight into the head-medium interface spatial charact
eristics.