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

Invited Paper MI-MoA1
Materials/Structures for High Areal Density Write Poles

Monday, November 3, 2003, 2:00 pm, Room 316

Session: Magnetic Recording and Magnetoresistive Structures
Presenter: M.K. Minor, Seagate Technology
Authors: M.K. Minor, Seagate Technology
T.J. Klemmer, Seagate Technology
M.A. Seigler, Seagate Technology
O. Mryasov, Seagate Technology
M. Kim, Northwestern University
A.J. Freeman, Northwestern University
Correspondent: Click to Email
The maximum effective write field of a head is related to head geometry and the saturation magnetization (4@pi@M@sub S@) of the pole material. Typically, head designs require a pole material at the air bearing surface (ABS) which exhibits a large 4@pi@M@sub S@, low coercivity, and a well-defined uniaxial anisotropy. The material with the largest known 4@pi@M@sub S@ at room temperature is exhibited by Fe@sub 65@Co@sub 35@ which has a value of ~2.4T. One of the problems with FeCo that prevents it from being used as a pole material is that the material is not uniaxial, therefore, it has nearly zero permeability which results in an inefficient write head. This lack of uniaxiality or magnetic "softness" is a direct result of the relatively large value of magnetocrystalline anisotropy exhibited by the high moment FeCo alloys. This talk will review some of the methods employed to induce magnetic softness in the high moment FeCo alloys. These methods include the effects of various processing conditions, the use of buffer layers, and laminated structures which are magnetostatically coupled. For each of these methods magnetic properties and film microstructure will be reviewed. A large portion of this talk will focus on FeCo multilayered structures fabricated via dc magnetron sputtering. Some modeling and experimental results will be presented. These results include enhanced moment prediction and effect of multilayering on anisotropy. The modeling results are compared to experimental results where we will show structural and magnetic properties of the FeCo multilayers.