Recent developments in high-moment electroplated materials for recording heads

Abstract

The continuous and rapid increase of areal density in magnetic data storage systems required a continuous increase of the coercivity of the storage media. In order to be able to record on these everhigher-coercivity media, new soft magnetic materials for pole tips with increased magnetic moment had to be developed. Significant progress has been made during the last few years in electroplating alloys with high saturation magnetic flux density for use in writing heads. We review recent progress made in this area, with particular emphasis on the work done at IBM since the review paper on the subject was published in this journal in 1998 by Andricacos and Robertson. Reviewed here are the high-moment alloys of NiFe, particularly in the very high iron range [an extension of permalloy (Ni 80 Fe 20) and Ni 45 Fe 55 ]; very-high-cobalt CoFeCu alloys; ternary CoNiFe; and binary iron-rich CoFe alloys. With the latter binary alloy films, we have demonstrated that it is possible to reach by electroplating the saturation flux density limit of 2.4-2.5 T reported for cast alloys. Since the electroplating of good-magneticquality iron-rich CoFe alloys posed a considerable challenge, the behavior of the CoFe plating system was studied in detail, using in situ surface pH measurements and a rotating-cylinder Hull cell.

Magnetic structuring of linear copper electrodeposits

“…Addition of non-electroactive GdCl 3 to the electrolyte inverts the structuring of the electrodeposits, producing thick dendritic growth in regions where the field is smallest. Electrodeposition is widely used method to prepare thick films of ferromagnetic metals and alloys such as permalloy for use as cores or shields in thin film heads 1 or cores in on-chip inductors. 2 The application of a magnetic field during deposition of these ferromagnetic metals or alloys may introduce crystallographic or atomic-scale texture, which can influence the anisotropy and magnetic reversal in the electrodeposited material.…”

Magnetotransport Properties of Co-Au Granular Alloys

“…Magnetic alloys with interesting magnetotransport and magnetic properties have been the subject of intense investigations due to their significance in fundamental physics [1]- [5] and application in electronics [6], [7] and in the automobile [8], [9], and biomedical sectors [10]- [13]. Many novel nanomaterials have been developed from the combination of ferromagnetic 3-d transition metals and non-magnetic group IB metals at an atomic scale [6], [14]- [20], and more are expected to emerge as the research continues.…”

“…Many novel nanomaterials have been developed from the combination of ferromagnetic 3-d transition metals and non-magnetic group IB metals at an atomic scale [6], [14]- [20], and more are expected to emerge as the research continues. Usually, 3-d transition ferromagnetic metals exhibit MR effect by virtue of their nature as these materials possess interesting electronic configurations where the 4s sub-shells are occupied leaving behind their 3-d shells unfilled.…”

Local atomic arrangement in mechanosynthesized Co x Fe1−x−y Ni y alloys studied by Mössbauer spectroscopy

“…The aim of this work is to provide an interpretation of the shape of HMF distributions for a series of Co x Fe 1-x-y Ni y alloys prepared by mechanical alloying (MA). As it was proved by several authors [16][17][18][19], the Co x Fe 1-x-y Ni y alloys exhibit soft magnetic properties and can be used as a head core material in magnetic storage devices.…”