High saturtion magnetization material and magnetic head fabricated therefrom

A magnetic material which may be employed as a thin film magnetic layer within magnetic heads, and a method for forming the magnetic material as a thin film magnetic layer for use within magnetic heads. The magnetic material has an elemental composition comprising about 40 to about 60 weight percent iron, about 40 to about 60 weight percent nickel and about 0.002 to about 1 weight percent tin. The magnetic material may be formed as a thin film magnetic layer for use within a magnetic head through an electrochemical plating method employing an aqueous plating solution comprising iron (II) ions, nickel (II) ions and tin (II) ions. When electrodeposited and anisotropically magnetically aligned, or when thermally annealed and anisotropically magnetically aligned the thin film magnetic layer possess a higher saturation magnetization, a higher anisotropy, a comparable easy axis coercivity, a lower hard axis permittivity and a higher resistivity than conventional thin film magnetic layers formed of permalloy (nickel-iron 80:20 w/w) alloys.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The present invention provides a magnetic material and a method for 
fabricating the magnetic material into a magnetic inductor element within 
a magnetic head, where the magnetic material when fabricated into the 
magnetic inductor element possesses: (1) a high saturation magnetization; 
(2) a high magnetic anisotropy; (3) a low easy axis coercivity; (3) a high 
hard axis magnetic permittivity; and (4) a high resistivity. It has been 
found experimentally that a magnetic material which when fabricated into a 
magnetic inductor element employed within a magnetic head simultaneously 
possesses the foregoing properties has an elemental composition 
comprising: (1) about 40 to about 60 weight percent iron; (2) about 40 to 
about 60 weight percent nickel; and (3) about 0.002 to about 1 weight 
percent tin. More preferably, the magnetic inductor material has an 
elemental composition comprising: (1) about 54 to about 56 weight percent 
iron; (2) about 44 to about 46 weight percent nickel; and (3) about 0.2 to 
about 0.5 weight percent tin. Yet more preferably, the magnetic inductor 
material has an elemental composition consisting essentially of (1) about 
40 to about 60 weight percent iron; (2) about 40 to about 60 weight 
percent nickel; and (3) about 0.002 to about 1 weight percent tin. Most 
preferably, the magnetic inductor material has an elemental composition 
consisting essentially of: (1) about 54 to about 56 weight percent iron; 
(2) about 44 to about 46 weight percent nickel; and (3) about 0.2 to about 
0.5 weight percent tin. 
The magnetic material of the present invention may be employed in forming 
magnetic inductor elements within magnetic heads including but not limited 
to inductive write magnetic heads, inductive read magnetic heads, 
inductive read-write magnetic heads and magnetoresistive (MR) read-write 
magnetic heads (i.e. inductive write/magnetoresistive (MR) read magnetic 
heads). Advantageously, the magnetic material of the present invention may 
also be employed in forming magnetic shield layers within any of the 
magnetic heads as listed above, as well as within any of several 
additional types of magnetic heads. Thus, the magnetic material of the 
present invention may also be employed in forming a merged 
magnetoresistive (MR) read-write magnetic head where one of the magnetic 
inductor pole layers within the merged magnetoresistive (MR) read-write 
magnetic head simultaneously serves as a shield layer within the merged 
magnetoresistive (MR) read-write magnetic head. Similarly advantageously, 
the magnetic material of the present invention may also be employed in 
forming magnetic flux guides within magnetic sensors employed within 
magnetic sensing applications. 
Referring now to FIG. 1 to FIG. 4, there is shown a series of schematic 
cross-sectional diagrams illustrating the results of progressive stages in 
fabricating within a magnetoresistive (MR) read-write head employed within 
digitally encoded magnetic data storage and retrieval a pair of magnetic 
inductor elements formed from the magnetic material of the present 
invention. The pair of magnetic inductor elements is formed in accord with 
a preferred embodiment of a method of the present invention. Shown in FIG. 
1 is a schematic cross-sectional diagram of the magnetoresistive (MR) 
read-write head at an early stage in its fabrication. 
Shown in FIG. 1 is a substrate 10 having formed thereupon or thereover 
several layers employed in forming a magnetoresistive (MR) read-write head 
employed in digitally encoded magnetic data storage and retrieval. Within 
FIG. 1, the substrate 10, as well as the several layers formed thereupon 
or thereover are illustrated from the view of the air bearing surface 
(ABS) of the magnetoresistive (MR) read-write head. Within FIG. 1, the 
layers formed upon or over the substrate 10 include: (1) a first 
dielectric layer 12 which has formed therein; (2) a magnetoresistive (MR) 
sensor element layer 14; (3) a first shield layer 11 and a second shield 
layer 16 formed contacting opposite sides of the first insulator layer 12; 
(4) a second insulator layer 18 formed upon the second shield layer 16; 
(5) a blanket first seed layer 20 formed upon the second dielectric layer 
18; and (6) a pair of patterned first photoresist layers 22a and 22b 
formed upon the blanket first seed layer 20. Each of the foregoing 
substrate and layers may be formed through methods and materials as are 
conventional in the art of magnetoresistive (MR) read-write head 
fabrication. 
For example, although it is known in the art of magnetoresistive (MR) 
read-write head fabrication that substrates are typically formed of 
non-magnetic ceramic materials such as but not limited to borides, 
nitrides, carbides and oxides, for the preferred embodiment of the present 
invention, the substrate 10 is preferably, although not exclusively, 
formed of an alumina-titanium carbide non-magnetic ceramic material as is 
common in the art of magnetoresistive (MR) read-write head fabrication. 
The substrate 10 is preferably formed of dimensions such that there may 
readily be fabricated from the substrate 10 a slider employed within a 
direct access storage device (DASD) magnetic data storage enclosure. 
Similarly, although it is also known in the art of magnetoresistive (MR) 
read-write head fabrication that dielectric layers may be formed through 
any of several methods and materials, including but not limited to 
chemical vapor deposition (CVD) methods, plasma enhanced chemical vapor 
deposition (PECVD) methods and physical vapor deposition (PVD) sputtering 
methods through which may be formed dielectric layers of dielectric 
materials including but not limited to silicon oxide dielectric materials, 
silicon nitride dielectric materials and aluminum oxide dielectric 
materials, for the preferred embodiment of the present invention both the 
first dielectric layer 12 and the second dielectric layer 18 are each 
preferably formed of an aluminum oxide dielectric material formed over the 
substrate 10 through a physical vapor deposition (PVD) sputtering method 
to a thickness of from about 50 to about 500 angstroms each, as is common 
in the art of magnetoresistive (MR) read-write head fabrication. 
With respect to the magnetoresistive (MR) sensor element layer 14, the 
magnetoresistive (MR) sensor element layer 14 preferably comprises a 
multilayer formed of a permalloy magnetoresistive (MR) layer 
longitudinally magnetically exchange biased and aligned through coupling 
with a pair of patterned antiferromagnetic layers formed thereupon of an 
iron-manganese alloy, as is common in the art of magnetoresistive (IR) 
read-write head fabrication. Other materials may, however, be employed in 
forming the magnetoresistive (MR) sensor element layer 14. Preferably the 
permalloy magnetoresistive (MR) layer within the magnetoresistive (MR) 
sensor element layer 14 is formed to a thickness of from about 50 to about 
500 angstroms, and the patterned anti-ferromagnetic layers formed 
thereupon define a trackwidth upon the permalloy magnetoresistive (MR) 
layer of from about 0.5 to about 5 microns. 
Although the first shield layer 11 and the second shield layer 16 within 
the magnetoresistive (MR) read-write head whose air bearing surface (ABS) 
is illustrated in FIG. 1 may in addition to being formed through methods 
and materials as are conventional in the art of magnetoresistive (MR) 
read-write head fabrication also be formed from the magnetic material of 
the present invention, within the magnetoresistive (MR) read-write head of 
the preferred embodiment of the present invention, the first shield layer 
11 and the second shield layer 16 are each preferably formed through 
methods and materials as are conventional in the art of magnetoresistive 
(MR) read-write head fabrication. Such methods and materials typically, 
although not exclusively, provide shield layers formed of magnetic 
materials such as but not limited to permalloy magnetic materials 
deposited through methods including but not limited to physical vapor 
deposition (PVD) sputtering methods. Thus, for the preferred embodiment of 
the magnetoresistive (MR) read-write head of the present invention, the 
first shield layer 11 and the second shield layer 16 are each preferably 
formed of a permalloy magnetic material formed to a thickness of from 
about 1 to about 4 microns contacting opposite sides of the first 
dielectric layer 12 through a physical vapor deposition (PVD) sputtering 
method, although other methods and materials may also be employed in 
forming the first shield layer 11 and the second shield layer 16. 
With respect to the blanket first seed layer 20 as illustrated in FIG. 1, 
the blanket first seed layer 20 may be formed from any of several 
conductive seed materials which are conventionally employed in forming 
blanket seed layers upon which are subsequently electroplated conductor 
materials within magnetic head fabrications. Such conductive seed 
materials conventionally include but are not limited to permalloy, copper, 
copper alloy, aluminum, aluminum alloy, titanium and titanium alloy 
conductor seed materials formed through methods including but not limited 
to thermally assisted evaporation methods, electron beam assisted 
evaporation methods, chemical vapor deposition (CVD) methods and physical 
vapor deposition (PVD) sputtering methods. Through similar deposition 
methods, the blanket first seed layer 20 may also be formed from an 
iron-nickel-tin alloy of composition in accord with the present invention. 
For the magnetoresistive (MR) read-write head of the preferred embodiment 
of the present invention, the blanket first seed layer 20 is preferably 
formed of a copper containing conductive seed material, as is most common 
in the art of magnetic head fabrication, although other conductive seed 
materials may also be employed in forming the blanket first seed layer 20. 
Preferably, the blanket first seed layer 20 so formed is formed to a 
thickness of from about 500 to about 5000 angstroms. 
Finally, the patterned photoresist layers 22a and 22b as illustrated in 
FIG. 1 may similarly be formed from any of several photoresist materials 
as are conventionally employed in the art of magnetoresistive (MR) 
read-write head fabrication, including but not limited to photoresist 
materials selected from the general groups of photoresist materials 
including but not limited to positive photoresist materials and negative 
photoresist materials. For the preferred embodiment of the present 
invention, the patterned photoresist layers 22a and 22b may be formed of 
either a positive photoresist material or a negative photoresist material. 
Preferably, the patterned photoresist layers 22a and 22b are each formed 
upon the blanket first seed layer 20 to a thickness of from about 10000 to 
about 50000 angstroms to define an aperture of width W1, as illustrated in 
FIG. 1, preferably from about 0.5 to about 5 microns leaving exposed an 
equivalent width of the blanket first seed layer 20. 
Referring now to FIG. 2, there is shown a schematic cross-sectional diagram 
illustrating the results of further processing of the magnetoresistive 
(MR) read-write head the schematic cross-sectional diagram of whose air 
bearing surface (ABS) is illustrated in FIG. 1. Shown in FIG. 2 is a 
schematic cross-sectional diagram of the air bearing surface (ABS) of a 
magnetoresistive (MR) read-write head otherwise equivalent to the air 
bearing surface (ABS) of the magnetoresistive (MR) read-write head whose 
schematic cross-sectional diagram is illustrated in FIG. 1, but wherein 
there is formed through an electroplating method a plated first magnetic 
inductor layer 24 upon the blanket first seed layer 20 within the aperture 
defined by the patterned first photoresist layers 22a and 22b. The plated 
first magnetic inductor layer 24 is preferably formed through an 
electrochemical plating method in accord with the preferred embodiment of 
the present invention to provide the plated first magnetic inductor layer 
24 which has an elemental composition, as noted above, preferably 
comprising: (1) about 40 to about 60 weight percent iron; (2) about 40 to 
about 60 weight percent nickel; and (3) about 0.002 to about 1 weight 
percent tin. Preferably, the plated first magnetic inductor layer 24 is 
plated to a thickness no greater than the thickness of the patterned first 
photoresist layers 22a and 22b, which will provide the plated first 
magnetic inductor layer 24 of typical thickness from about 1 to about 4 
microns, with nominally vertical sidewalls. 
Although FIG. 2 illustrates within the preferred embodiment of the present 
invention the plated first magnetic inductor layer 24, within the method 
of the present invention, in general, equivalent first magnetic inductor 
layers (or equivalent subsequent magnetic inductor layers) may be formed 
through methods other than plating methods, provided that the above 
specified elemental compositions are provided within equivalent first 
magnetic inductor layers (as well as the equivalent subsequent magnetic 
inductor layers) formed through the methods other than the plating 
methods. The other methods may include, but are not limited to evaporation 
methods and sputtering methods. 
In order to provide the plated first magnetic inductor layer 24 with the 
foregoing preferred elemental composition, there is preferably employed 
within the preferred embodiment of the present invention an aqueous 
plating solution comprising: (1) about 0.4 to about 0.9 moles per liter 
iron (II) ion; (2) about 0.2 to about 0.8 moles per liter nickel (II) ion; 
and (3) about 0.002 to about 0.010 moles per liter tin (II) ions. Within 
the preferred embodiment of the present invention the foregoing metal ion 
concentrations are preferably provided by corresponding concentrations of: 
(1) iron (II) sulfate; (2) equal portions of nickel (II) sulfate and 
nickel (II) chloride; and (3) tin (II) acetate. 
In addition to the metal ions, the aqueous plating solution also preferably 
comprises several additives and supporting electrolytes which provide for 
optimal plating characteristics of the aqueous plating solution. The 
additives and electrolytes preferably include, but are not limited to: (1) 
boric acid at about 0.3 to about 0.6 moles per liter; (2) sodium saccharin 
at about 0.005 to about 0.02 moles per liter; (3) sodium acetate at about 
0.05 to about 0.09 moles per liter; and (4) sufficient acid or base to 
maintain a pH of from about 2.0 to about 3.0. 
In addition to the metal ions, additives and supporting electrolytes 
comprising the aqueous plating solution, when forming the plated first 
magnetic inductor layer 24 through the electrochemical plating method 
employing the aqueous plating solution there are also employed several 
control parameters and limits within the electrochemical plating method, 
the parameters and limits including but not limited to: (1) a plating 
solution temperature of from about 20 to about 35 degrees centigrade; (2) 
a plating current density of from about 5 to about 20 milli-amps per 
square centimeter, (3) a plating voltage of from about 0.5 to about 5 
volts; and (4) an agitation rate of from about 15 to about 200 
reciprocations per minute. 
In order to impart desirable magnetic properties to the plated first 
magnetic inductor layer 24 it is preferred within the preferred embodiment 
of the present invention to anisotropically magnetically align the 
magnetic domains within the plated first magnetic inductor layer 24. The 
magnetic domains within the plated first magnetic inductor layer 24 are 
preferably anisotropically magnetically aligned through exposure to a 
magnetic field H, as illustrated in FIG. 2, external to the plated first 
magnetic inductor layer 24 and within the plane of the air bearing surface 
(ABS) of the magnetoresistive (MR) read-write head whose schematic 
cross-sectional diagram is illustrated in FIG. 2. While the magnetic field 
H external to the plated first magnetic inductor layer 24 may be provided 
either during the process of electrochemically plating the plated first 
magnetic inductor layer 24 or after the plated first magnetic inductor 
layer 24 has been plated and formed upon the blanket first seed layer 20, 
within the preferred embodiment of the present invention the plated first 
magnetic inductor layer 24 is preferably anisotropically magnetically 
aligned while the plated first magnetic inductor layer 24 is being formed 
through the electrochemical plating method. Preferably, the plated first 
magnetic inductor layer 24 is anisotropically magnetically aligned in the 
external magnetic field H having a magnetic field strength of from about 
100 to about 3000 gauss. 
Upon forming and anisotropically magnetically aligning the plated magnetic 
inductor layer 24 as illustrated in FIG. 2, there is formed the plated 
magnetic inductor layer 24 typically possessing: (1) a saturation 
magnetization of from about 12 to about 16 kgauss; (2) a magnetic 
anisotropy of from about 8 to about 16 oersteds; (3) an easy axis 
coercivity of from about 0.3 to about 1.0 oersteds; (4) a hard axis 
magnetic permittivity of from about 1000 to about 4000; and (5) a 
resistivity of about 25 to about 70 micro-ohm.cm. 
In order to assure optimal properties within the plated first magnetic 
inductor layer 24 it is also possible within the present invention to 
simultaneously thermally anneal and anisotropically magnetically align the 
plated first magnetic inductor layer 24. Under such circumstances, the 
plated first magnetic inductor layer 24 is simultaneously thermally 
annealed at a temperature of from about 120 to about 300 degrees 
centigrade and anisotropically magnetically aligned within the external 
magnetic field H of strength of from about 100 to about 3000 gauss. The 
simultaneous thermal annealing and anisotropic magnetic aligning of the 
plated first magnetic inductor layer 24 may be undertaken either in place 
of or in addition to the anisotropic magnetic aligning in absence of 
thermal annealing, as discussed above, but the simultaneous thermal 
annealing and anisotropic magnetic aligning may not practicably be 
undertaken while the plated first magnetic inductor layer 24 is being 
formed. When the plated first magnetic inductor layer 24 is simultaneously 
thermally annealed and anisotropically magnetically aligned, the plated 
first magnetic inductor layer 24 typically similarly possesses: (1) a 
saturation magnetization of from about 12 to about 16 kgauss; (2) a 
magnetic anisotropy of from about 8 to about 16 oersteds; (3) an easy axis 
coercivity of from about 0.3 to about 1.0 oersteds; (3) a hard axis 
magnetic permittivity of from about 1000 to about 4000; and (4) a 
resistivity of from about 25 to about 70 micro-ohm.cm. 
Referring now to FIG. 3, there is shown a schematic cross-sectional diagram 
illustrating the results of further processing of the magnetoresistive 
(MR) read-write head whose schematic cross-sectional diagram is 
illustrated in FIG. 2. Shown in FIG. 3 is a schematic cross-sectional 
diagram of the air bearing surface (ABS) of a magnetoresistive (MR) 
read-write head largely equivalent to the air bearing surface (ABS) of the 
magnetoresistive (MR) read-write head whose schematic cross-sectional 
diagram is illustrated in FIG. 2, but from whose surface there has first 
been removed the patterned first photoresist layers 22a and 22b. The 
patterned first photoresist layers 22a and 22b may be removed through 
methods as are conventional in the art, which will typically, although not 
exclusively, include wet chemical etch methods and reactive ion etch (RIE) 
dry plasma etch methods. Subsequent to removing the patterned first 
photoresist layers 22a and 22b, the blanket first seed layer 20 as 
illustrated in FIG. 2 is patterned, typically through an ion milling 
method employing the plated first magnetic inductor layer 24 as a mask, to 
form the patterned first seed layer 20a. Together, the plated first 
magnetic inductor layer 24 and the patterned first seed layer 20a, as 
illustrated in FIG. 3, form a first magnetic inductor pole tip within the 
air bearing surface (ABS) of the magnetoresistive (MR) read-write head 
whose schematic cross-sectional diagram is illustrated in FIG. 3. 
As is illustrated in FIG. 3, there is then formed upon exposed portions of 
the second dielectric layer 18, the patterned first seed layer 20a and the 
plated first magnetic inductor layer 24 a third dielectric layer 26 having 
formed thereupon a blanket second seed layer 28. The blanket second seed 
layer 28 in turn has formed thereupon a pair of patterned second 
photoresist layers 30a and 30b, and the portion of the blanket second seed 
layer 28 exposed through the patterned second photoresist layers 30a and 
30b has formed thereupon a plated second magnetic inductor layer 32. 
Within the preferred embodiment of the present invention, the third 
dielectric layer 26 is preferably formed through methods, materials and 
dimensions analogous or equivalent to the methods, materials and 
dimensions employed in forming the second dielectric layer 18 or the first 
dielectric layer 12. Similarly, within the preferred embodiment of the 
present invention the blanket second seed layer 28 is preferably formed 
through methods, materials and dimensions analogous or equivalent to the 
methods, materials and dimensions employed in forming the blanket first 
seed layer 20. In addition, within the preferred embodiment of the present 
invention the patterned second photoresist layers 30a and 30b are 
preferably formed through methods, materials and dimensions analogous or 
equivalent to the methods, materials and dimensions employed in forming 
the patterned first photoresist layers 22a and 22b. Finally, within the 
preferred embodiment of the present invention the plated second magnetic 
inductor layer 32 is preferably formed through methods, materials and 
dimensions analogous or equivalent to the methods, materials and 
dimensions employed in forming the plated first magnetic inductor layer 
24. Within the preferred embodiment of the present invention the plated 
second magnetic inductor layer 32 is also anisotropically magnetically 
aligned or optionally thermally annealed and anisotropically magnetically 
aligned in a manner analogous or equivalent to manner through which the 
plated first magnetic inductor layer 24 is either anisotropically 
magnetically aligned or thermally annealed and anisotropically 
magnetically aligned, as disclosed above. 
Referring now to FIG. 4, there is shown a schematic cross-sectional diagram 
illustrating the results of further processing of the magnetoresistive 
(MR) read-write head whose schematic cross-sectional diagram is 
illustrated in FIG. 3. Shown in FIG. 4 is a schematic cross-sectional 
diagram of the air bearing surface (ABS) of a magnetoresistive (MR) 
read-write head otherwise equivalent to the magnetoresistive (MR) 
read-write head whose schematic cross-sectional diagram is illustrated in 
FIG. 3, but: (1) from whose surface has been removed the patterned second 
photoresist layers 30a and 30b; (2) from whose blanket second seed layer 
28 has been formed a patterned second seed layer 28a; and (3) upon whose 
surface is then formed a planarized fourth dielectric layer 34. Within the 
preferred embodiment of the present invention, the patterned second 
photoresist layers 30a and 30b are preferably removed through methods and 
materials analogous or equivalent to the methods and materials employed in 
removing from the magnetoresistive (MR) read-write head whose schematic 
cross-sectional diagram is illustrated in FIG. 2 the patterned first 
photoresist layers 22a and 22b. Similarly, within the preferred embodiment 
of the present invention the patterned second seed layer 28a is formed 
from the blanket second seed layer 28 through methods and materials 
analogous or equivalent to the methods and materials through which the 
patterned first seed layer 20a as illustrated in FIG. 3 is formed from the 
blanket first seed layer 20 as illustrated in FIG. 2. Finally, within the 
preferred embodiment of the present invention, the fourth dielectric layer 
34 is preferably formed upon the exposed portions of the third dielectric 
layer 26, the patterned second seed layer 28a and the plated second 
magnetic inductor layer 32 through methods and materials analogous or 
equivalent to the methods and materials employed in forming the planarized 
third insulator layer 26 upon the exposed portions of the planarized 
second dielectric layer 18, the patterned first seed layer 20a and the 
plated first magnetic inductor layer 24. As is understood by a person 
skilled in the art, the plated second magnetic inductor layer 32 and the 
patterned second seed layer 28a form a second magnetic inductor pole tip 
within the air bearing surface (ABS) of the magnetoresistive (MR) 
read-write head whose schematic cross-sectional diagram is illustrated in 
FIG. 4. 
As is understood by a person skilled in the art, there may, in addition to 
the various layers illustrated in FIG. 4, also be formed within the 
magnetoresistive (MR) read-write head whose schematic cross-sectional 
diagram is illustrated in FIG. 4 additional layers as are conventional in 
the art of magnetoresistive (MR) read-write head fabrication. The 
additional layers may include, but are not limited to, additional shield 
layers, conductor layers, dielectric layers, interconnection layers and 
passivation layers. 
Similarly, as is also understood by a person skilled in the art and 
discussed briefly above, there may also be formed in accord with the 
methods and materials outlined for the preferred embodiment of the present 
invention a merged magnetoresistive (MR) read-write head or an inductive 
read-write magnetic head. In comparison with the magnetoresistive (MR) 
read-write head whose schematic cross-sectional diagram is illustrated in 
FIG. 4, a merged magnetoresistive (MR) read-write head typically excludes: 
(1) the second magnetic inductor pole tip comprised of the patterned 
second seed layer 28a and the plated second magnetic inductor layer 32; 
and (2) the fourth dielectric layer, while employing the second shield 
layer 16 simultaneously as a shield layer and as a magnetic inductor pole 
layer. Similarly, in comparison with the magnetoresistive (MR) read-write 
head whose schematic cross-sectional diagram is illustrated in FIG. 4, an 
inductive magnetic read-write head typical excludes the first shield layer 
11, the second shield layer 16, the magnetoresistive sensor element layer 
14, the first dielectric layer 12 and the second dielectric layer 18. 
EXAMPLE 
A three inch diameter silicon wafer was obtained and there was formed 
thereupon a blanket seed layer of a permalloy conductive seed material to 
a thickness of about 1000 angstroms. The blanket seed layer was formed 
through a physical vapor deposition (PVD) sputtering method. Upon the 
blanket seed layer there was then formed through an electrochemical 
plating method in accord with the preferred embodiment of the present 
invention a plated magnetic layer of an elemental composition comprising 
iron, nickel and tin. 
The magnetic layer was plated from an aqueous plating solution comprising: 
(1) about 0.75 moles per liter iron (II) sulfate; (2) about 0.25 moles per 
liter nickel (II) chloride; (3) about 0.30 moles per liter nickel (II) 
sulfate; (4) about 0.0045 moles per liter tin (II) acetate; (5) about 0.45 
moles per liter boric acid; (6) about 0.01 moles per liter sodium 
saccharin; (7) about 0.07 moles per liter sodium acetate; (8) sufficient 
acid or base to maintain a pH of about 2.7; and (9) about 0.1 gram per 
liter FC-95 surfactant available from 3M Company, St. Paul, Minn. 
The electrochemical plating method employing the aqueous plating solution 
was undertaken at: (1) a plating temperature of about 25 degrees 
centigrade; (2) a plating current density of about 10 milli-amps per 
square centimeter; (3) a plating voltage of about 2.5 volts; (4) an 
agitation rate of about 60 reciprocations per minute; and (5) an applied 
external magnetic field of about 1000 gauss, thus forming an 
anisotropically magnetically aligned plated magnetic layer. The 
anisotropically magnetically aligned plated magnetic layer was formed to a 
thickness of about 4 microns. The elemental composition of the 
anisotropically magnetically aligned plated magnetic layer was determined 
by energy dispersive x-ray analysis to be about 55 weight percent iron, 
about 45 weight percent nickel and about 0.2 weight percent tin. The 
magnetic properties of the anisotropically magnetically aligned plated 
magnetic layer were then determined through methods as are conventional in 
the art. The anisotropically magnetically aligned plated magnetic layer 
was then thermally annealed at a temperature of about 210 degrees 
centigrade for a time period of about 180 minutes, within an external 
magnetic field of about 1500 gauss, to form from the anisotropically 
magnetically aligned plated magnetic layer a thermally annealed and 
anisotropically magnetically aligned plated magnetic layer. The magnetic 
properties of the thermally annealed and anisotropically magnetically 
aligned plated magnetic layer were also determined through methods as are 
conventional in the art. The magnetic properties of the anisotropically 
magnetically aligned plated magnetic layer and the thermally annealed and 
anisotropically magnetically aligned plated magnetic layer are reported in 
Table I, along with corresponding representative values for equivalent 
magnetic properties determined for a permalloy magnetic layer of otherwise 
equivalent dimensions. 
TABLE I 
______________________________________ 
Satura- Resistivity 
tion Magnetic Easy Axis 
Hard Axis 
(micro- 
Magnet. Anistrop. 
Coercivity 
Permittiv- 
ohm. 
Magnetic Layer 
(kgauss) 
(oersteds) 
(oersteds) 
ity cm) 
______________________________________ 
Anisotrop. 
15.5 9 0.4 1700 55 
Align. 
Fe/Ni/Sn 
Anneal/Align. 
15.5 10.5 0.3 1500 55 
Fe/Ni/Sn 
Permalloy 
9 4 0.4 2200 20 
______________________________________ 
As is seen from review of the data in Table I, there is formed through the 
method of the present invention an anisotropically magnetically aligned 
magnetic layer with generally superior magnetic properties in comparison 
with a permalloy magnetic material layer of otherwise equivalent 
dimensions. In addition, as is also seen from review of the data in Table 
I, there is formed through the method of the present invention a thermally 
annealed and anisotropically magnetically aligned magnetic layer with 
comparable properties in comparison with the anisotropically magnetically 
aligned magnetic layer. 
Although not specifically directed towards the magnetic properties of the 
anisotropically magnetically aligned magnetic layer or the thermally 
annealed and anisotropically magnetically aligned magnetic layer formed in 
accord with the examples, the film stress of the anisotropically 
magnetically aligned layer was also measured and determined to be about 
5E8 dynes per square centimeter. A film stress in this range is comparable 
with film stresses typically observed for permalloy layers employed within 
various locations within magnetic heads, including but not limited to 
magnetoresistive (MR) read-write heads. 
As is understood by a person skilled in the art, the preferred embodiment 
and examples of the present invention are illustrative of the present 
invention rather than limiting of the present invention. Revisions and 
modifications may be made to methods, structures and dimensions through 
which is formed the preferred embodiment and examples of the present 
invention while still providing embodiments and examples which are within 
the spirit and scope of the present invention, as defined by the 
accompanying claims.