Resolution enhancement of shielded MR heads for perpendicular magnetic recording

Abstract

3 1 0 > e 0 8 v) .-.-0 6 -U 0 4 -b, m 0 24 2 0 2 -E Abstrud-hnpruvement of high linear density response of shielded MR heads by introducing perpendicular magnetic recording is discussed. A theoretical estimation shows that narrower pulse width can be obtained with the same MR head than in longitudinal recording. A 200 nm shield gap MR head and a differentiator demonstrate D , of 270 kFRPI and PW, of 140 nm. SN ratio at high densities is also improved with the differentiation. (a) perpendicular --flying height= 50 nm -recording layer= 50 nrn -shield gap= 200 nm ----L-.= 00-=--"---J

Quantification of Perpendicular Magnetic Recording with Double Layer Media

“…The curve almost corresponds to that of longitudinal magnetization with a much smaller spacing of 20 nm. The linear relation between the Dso and PW so has been confirmed [10]; the Dso are inversely proportional to the PW so' whose coefficient is as same as the case of longitudinal [11], i.e. DSO[kFRPI)= 37100/PW SO[nm) ' It is well known that a reduction of magnetic spacing between head and disk improves all read/write performance except for tribological issues.…”

Extremely low inductance thin-film single-pole head on flying slider

“…Since the D,, are restricted by the shield gap length of 270 nm of the MR head, less gap length improves it. A differentiator may be convenient for an h4R head in perpendicular magnetic recording, which will also increase the D,, [2]. The overwrite characteristics are also satisfactory as shown in Fig 7. Less than -30 dB for the type A head with the thin film return path one, or -40 dE3 for the type B head with the ferrite slider one, are demonstrated.…”

“…Although a regular merged MR head can be used in perpendicular magnetic recording, also with a double layer perpendicular medium [l], a single-pole head is another candidate for a writing head [2]. It is thus interesting to examine a practical single pole-head incorporating an MR sensor.…”