AVS 50th International Symposium
    Magnetic Interfaces and Nanostructures Monday Sessions
       Session MI-MoA

Paper MI-MoA3
Influence of Pd and Pt Buffers on the Soft Magnetic Properties of Fe@sub 70@Co@sub 30@ Thin Films

Monday, November 3, 2003, 2:40 pm, Room 316

Session: Magnetic Recording and Magnetoresistive Structures
Presenter: C.L. Platt, Seagate Technology
Authors: C.L. Platt, Seagate Technology
J.K. Howard, Seagate Technology
D.J. Smith, Arizona State University
Correspondent: Click to Email
Writer pole materials with large saturation magnetization are desired to maximize the available writing field for magnetic recording. A 5 nm thick Pd or Pt buffer layer is sufficient to significantly alter the magnetic and structural properties of sputtered high moment (2.4 T) Fe@sub 70@Co@sub 30@ thin films. A 50 nm thick FeCo film with no buffer grown on an amorphous SiO@sub 2@ substrate had a coercivity of 40 Oe and showed no evidence of an induced easy axis, although the film was grown in an applied field of 50 Oe. This is typical of high moment FeCo alloys which usually do not exhibit soft magnetic properties due to large magnetostriction and difficulty controlling magnetic ripple structure. Use of 5 nm Pd or Pt buffer reduced the coercivity of 50 nm FeCo films to about 15 Oe with a definable easy axis. Structurally, the primary influence of the Pd or Pt buffer was a reduction in the average FeCo grain size and more clearly defined columnar grain boundaries. This is similar to what has been observed using other fcc buffers.@footnote 1,2@ Growing thicker FeCo films (200 nm) resulted in a significant increase in average column width and a loss of soft magnetic properties regardless of the buffer. @FootnoteText@ @footnote 1@H. S. Jung, W. D. Doyle, J. E. Wittig, J. F. Al-Sharab, and J. Bentley, Appl. Phys. Lett. 81, 2415 (2002).@footnote 2@C. L. Platt, A. E. Berkowitz, D. J. Smith, and M. R. McCartney, J. Appl. Phys. 88, 2058 (2000).