Abstract:
A method and system provide a magnetic read and/or write transducer for use in disk drive. A read transducer has an air-bearing surface (ABS) and includes a read sensor, a nonmagnetic gap, a heater, and an expander. The nonmagnetic gap is adjacent to a portion of the read sensor and has a first coefficient of thermal expansion (CTE). The heater heats a portion of the magnetic read transducer. The expander is adjacent to a portion of the nonmagnetic gap and has a second CTE greater than the first CTE. The write transducer includes a pole, a coil, an insulator adjacent to and for insulating the coil, a heater and an expander. The expander has a CTE greater than the insulator&#39;s CTE.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 13/332,241, filed on Dec. 20, 2011, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     Disk drives typically use heads residing on sliders to read from and write to the magnetic media. Read and write transducers residing in the head are flown at a small, controlled spacing above the magnetic medium during read and write operations. Thermal actuators, or heaters, may be used to control the spacing between the media and the read or write transducer. More specifically, heat generated by the heater causes local thermal expansion of the head. The thermal expansion results in protrusions of the head near the air-bearing surface (ABS). Protrusions in portions of the head near the ABS locally reduce the spacing between the head and magnetic media. The heater can be driven to induce sufficient heating for contact between the head and media. Such an operation is known as touchdown. This touchdown is intentional and is generally performed on each drive during initial drive calibration. The heater may also be used to otherwise control the spacing between the head and media. 
     Although heaters can be used to control the protrusion of the head, there may be drawbacks. A heater is typically included in the write transducer, but may not be in the read transducer of a head. Consequently, there are offsets between the protrusion of the write transducer and the protrusion of the read transducer. 
     Portions of the read transducer may not have a sufficient protrusion to obtain the desired spacing between the read transducer and media (including touchdown). Further, even if the read transducer may protrude a sufficient amount, this may not be possible without inducing a protrusion in the write transducer that is larger than desired. Although multiple heaters may be included in a head, back end processing of the heat may be subject to significant variations. As a result, the heater in the read or write transducer may not be able lo generate sulficient heat to provide Ihe desired protrusion of the head. 
     Accordingly, what is needed is a system and method for providing improved touchdown detection. 
     BRIEF SUMMARY OF THE INVENTION 
     A method and system provide a magnetic read and/or write transducer for use in disk drive. A read transducer has an air-bearing surface (ABS) and includes a read sensor, a nonmagnetic gap, a heater, and an expander. The nonmagnetic gap is adjacent to a portion of the read sensor and has a first coefficient of thermal expansion (CTE). The heater heats a portion of the magnetic read transducer. The expander is adjacent to a portion of the nonmagnetic gap and has a second CTE greater than the first CTE. The write transducer includes a pole, a coil, an insulator adjacent to and for insulating the coil, a heater and an expander. The expander has a CTE greater than the insulator&#39;s CTE 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a diagram of a portion of an exemplary embodiment of a disk drive including at least one heater. 
         FIG. 2  depicts a perspective view of an exemplary embodiment of a read transducer including an expander. 
         FIG. 3  depicts a perspective view of another exemplary embodiment of a read transducer including an expander. 
         FIG. 4  depicts a perspective view of another exemplary embodiment of a read transducer including an expander. 
         FIG. 5  depicts a side view of an exemplary embodiment of a write transducer including an expander. 
         FIG. 6  depicts a side view of another exemplary embodiment of a write transducer including an expander. 
         FIG. 7  depicts a side view of an exemplary embodiment of a head including a read transducer and a write transducer. 
         FIG. 8  is a flow chart depicting an exemplary embodiment of a method for fabricating a read transducer including an expander. 
         FIG. 9  is a flow chart depicting an exemplary embodiment of a method for fabricating a write transducer including an expander. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  is a diagram of a portion of an exemplary embodiment of a disk drive  50 , which may employ one or more heaters. For simplicity, components are omitted. In addition, for clarity,  FIG. 1  is not drawn to scale. The disk drive  50  includes a media  60  and a slider  70 . On the slider  70  resides head  80 , which includes a read transducer and/or a write transducer (not labeled) as well as at least one heater (not explicitly shown). The disk drive  50  is shown at touchdown. Consequently, the head  80  contacts the media  60  in the region that protrudes due to heater(s) (not shown). Thus, in the embodiment shown, the heater(s) in the disk drive may generate enough heat that the read transducer and/or write transducer may be controlled to have the desired spacing with the media. This includes allowing for touchdown when desired. 
       FIG. 2  depicts an exemplary embodiment of a portion of the magnetic head  80 . More specifically, a read transducer  100  is shown in  FIG. 2 . For simplicity, any other components of the head  80  are omitted and the media  60  is not shown in  FIG. 2 . For clarity,  FIG. 2  is not drawn to scale. Referring to  FIGS. 1-2 , the read transducer  100  is also described in the context of particular components and layers. However, in some embodiments, such layers may include sub-layer(s). In addition, some components may be moved, omitted, or combined with other components. 
     The read transducer  100  is used in reading from the media  60 . The read transducer  100  includes shields  102  and  104 , insulators  101  and  103 , read sensor  106 , heater  108  and expander  110 . The read sensor  106  may include a giant magnetoresistive sensor, such as a tunneling magnetoresistive junction. However, in other embodiments, the read sensor  106  may include other and/or additional components. In addition, other components such as magnetic bias structures, side shields, contacts and other structures are not shown. 
     In the embodiment shown, the shield  102  is shown between the heater  108  and the sensor  106 . Thus, the heater  108  and expander  110  reside in an insulating layer  101  that, for the purposes of the embodiment shown, is considered part of the read transducer  100 . Thus, the insulating layer  101  is considered adjacent to (near) the read sensor  106 . However, in other embodiments, the heater  108  and/or the expander  110  may be located elsewhere. Although the heater  108  and expander  110  are shown at particular locations in  FIGS. 1 and 2 , in other embodiments, these components  108  and  110  may be located elsewhere. The heater  108  is used to generate heat, which causes a local protrusion of the read transducer  100 . Thus, the heater  108  may be used to induce the protrusion causing touchdown, as shown in  FIG. 1 , and otherwise control the spacing of the head  80  to the media  60 . 
     The expander  110  is proximate to the heater  108 . The expander  110  is desired to be nonmagnetic. In the embodiment shown, the expander  110  is between the heater  108  and the ABS. However, in other embodiments, at least a portion of the expander overlaps the heater  108 . In the embodiment shown, the expander  110  is recessed from the ABS. Thus, any issues due to corrosion may be mitigated or avoided. However, in other embodiments, the expander  110  may extend to the ABS. The coefficient of thermal expansion (CTE) of the expander  110  is larger than the CTE of the insulator  101  surrounding the expander  110 . Thus, the expander  110  increases in size to a greater degree than the surrounding insulator  101  for the same temperature change. The CTE of the expander  110  may be at least twice the CTE of the insulator  101 . In some embodiments, the CTE of the expander  110  is at least three times the CTE of the insulator  101 . In some embodiments, the expander  110  may be a metal, such as copper having a CTE on the order of 16.5×10 −6 /K. Other materials including nonmetals may be used. However, metals may be preferred to improve the response time of the expander  110 . 
     The expander  110  is configured to improve the ability of the heater  108  to cause a protrusion of the read transducer  100  at the ABS. Thus, the CTE of the expander  110  is greater than the surrounding insulator  101 . In addition, the geometry of the expander  110  may be configured such that the change in size of the expander  110  due to heating by the heater  108  may be directional in nature. Thus, the expander  110  may be made relatively thin in the down track direction (vertically in  FIG. 2 ) and may have a length perpendicular to the ABS that is at least twice the width in the track width direction. Thus, the aspect ratio of the expander  110  may be at least two. In some embodiments, the aspect ratio of the expander  110  is at least five. The higher aspect ratio translates to a preferred direction of expansion: perpendicular to the ABS. Further, the expander  110  may be configured to overlap the active portion of the heater  108  in the track width direction. Thus, the width of the expander  110  in the track width direction may be at least as large as the width of the active portion of the heater  108  in the track width direction. Further, as viewed from the ABS, the expander  110  may be directly in front of, directly above, or directly below the active portion of the heater  108 . Thus, the expander  110  tends to overlap the active region of the heater in the track width direction. 
     In operation, current is driven through the heater  108 , which generates heat. In response, both the insulator  101  and the expander  110  experience an increase in temperature. Because they each have a nonzero CTE, the insulator  101  and expander  110  also change in size. However, because the expander  110  has a CTE that is greater than that of the insulator  101 , the expander  110  protrudes to a greater degree than the insulator  101 . In some embodiments, this difference is significant—two to three times or more. Further, the expander  110  may have a length perpendicular to the ABS that is greater than the remaining dimensions. Thus, the expander  110  tends to expand perpendicular to the ABS to a larger degree. The increase in thermal expansion, particularly coupled with the directionality of the thermal expansion, tends to cause the insulator  101 , the shield  102 , and other nearby components of the transducer  100  to protrude out toward the ABS. Thus, the expander  110  may enhance the thermally induced protrusion of the read transducer  100 . The desired protrusion of the transducer  100  may thus be achieved at a lower temperature, a greater protrusion may be achieved at the same temperature, and/or the desired protrusion may be attained despite variations in fabrication of the transducer  100 . In addition, because the expander  110  can provide the desired protrusion at lower temperatures, the heater  108  may be moved further from the sensor  106 . For example, the heater  108  may be placed further from ABS. Thus, the sensor  106  may be better protected from damage. 
       FIG. 3  depicts a perspective view of an exemplary embodiment of a portion of the magnetic head  80 . More specifically, a read transducer  100 ′ is shown in  FIG. 3 . For simplicity, any other components of the head  80  are omitted and the media  60  is not shown in  FIG. 3 . For clarity,  FIG. 3  is not drawn to scale. Referring to  FIGS. 1 and 3 , the read transducer  100 ′ is also described in the context of particular components and layers. However, in some embodiments, such layers may include sub-layer(s). In addition, some components may be moved, omitted, or combined with other components. The transducer  100 ′ is analogous to the transducer  100 . Consequently, analogous components are labeled similarly. The transducer  100 ′ thus includes shields  102 ′ and 104′, insulators  101 ′ and  103 ′, read sensor  106 ′, heater  108 ′ and expander  110 ′ that are analogous to shields  102  and  104 , insulators  101  and  103 , read sensor  106 , heater  108 , and expander  110 , respectively. The components  101 ′,  102 ′,  103 ′,  104 ′,  106 ′,  108 ′, and  110 ′ thus have a similar structure and function to the components  101 ,  102 ,  103 ,  104 ,  106 ,  108 , and  110 , respectively. Also shown is insulator  105 . 
     In the embodiment shown, the second shield  104 ′ is between the read sensor  106 ′ and the expander  110 ′ and heater  108 ′. Thus, the heater  108 ′ and expander  110 ′ reside in the insulator  105  that may be between the read transducer and a write transducer (not shown in  FIG. 3 ). Further, a portion of the expander  110 ′ overlaps the heater  108 ′. 
     The heater  108 ′ and expander  110 ′ function in an analogous manner to the heater  108  and expander  110 . Thus, a current is driven through the heater  108 ′, which generates heat. In response, both the insulator  105  and the expander  110 ′ experience an increase in temperature. Because it has a larger CTE, the expander  110 ′ changes size to a greater extent than the insulator  105 . Further, the expander  110 ′ may have a length perpendicular to the ABS that is greater than the remaining dimensions. Thus, the expander  110 ′ tends to expand perpendicular to the ABS to a larger extent. The increase in thermal expansion, particularly coupled with the directionality of the thermal expansion, tends to cause the insulator  105 , the shields  102 ′ and  104 ′, and other nearby components of the transducer  100 ′ to protrude out toward the ABS. In addition, because the expander  110 ′ can provide the desired protrusion at lower temperatures, the heater  108 ′ may be moved further from the sensor  106 ′. For example, the heater  108 ′ may be placed further from ABS. Thus, the sensor  106 ′ may be better protected from damage. 
     Thus, the transducer  100 ′ may share the benefits of the transducer  100 . Because of the expander  110 ′ the thermally induced protrusion of the read transducer  100 ′ may be enhanced. The desired protrusion of the transducer  100 ′ may thus be achieved at a lower temperature, a greater protrusion may be achieved at the same temperature, and/or the desired protrusion may be attained despite variations in fabrication of the transducer  100 ′. 
       FIG. 4  depicts a perspective view of an exemplary embodiment of a portion of the magnetic head  80 . More specifically, a read transducer  100 ″ is shown in  FIG. 4 . For simplicity, any other components of the head  80  are omitted and the media  60  is not shown in  FIG. 4 . For clarity,  FIG. 4  is not drawn to scale. Referring to  FIGS. 1 and 4 , the read transducer  100 ″ is also described in the context of particular components and layers. However, in some embodiments, such layers may include sub-layer(s). In addition, some components may be moved, omitted, or combined with other components. The transducer  100 ″ is analogous to the transducers  100  and  100 ′. Consequently, analogous components are labeled similarly. The transducer  100 ″ thus includes shields  102 ″ and  104 ″, insulators  101 ″ and  103 ″, read sensor  106 ″, heater  108 ″ and expander  110 ″ that are analogous to shields  102 / 102 ′ and  104 / 104 ′, insulators  101 / 101 ′ and  103 / 103 ′, read sensor  106 / 106 ′, heater  108 / 108 ′, and expander  110 / 110 ′, respectively. The components  101 ″,  102 ″,  103 ″,  104 ″,  106 ″,  108 ″, and  110 ″ thus have a similar structure and function to the components  101 / 101 ′,  102 / 102 ′,  103 / 103 ′,  104 / 104 ′,  106 / 106 ′,  108 / 108 ′, and  110 / 110 ′, respectively. 
     In the embodiment shown, the expander  110 ″ and heater  108 ″ are close to the shield  102 ″. Thus, the heater  108 ″ and expander  110 ″ again reside in the insulator  101 ″ that also adjoins the shield  102 ″. However, in this embodiment, a portion of the expander  110 ″ overlaps the heater  108 ″ in both the track width direction (as seen from the ABS) and perpendicular to the ABS. 
     The heater  108 ″ and expander  110 ″ function in an analogous manner to the heater  108 / 108 ′ and expander  110 / 110 ′. Thus, a current is driven through the heater  108 ″, which generates heat. In response, both the insulator  101 ″ and the expander  110 ″ experience an increase in temperature. Because it has a larger CTE, the expander  110 ″ changes size to a greater extent than the insulator  101 ″. Further, the expander  110 ″ may have a length perpendicular to the ABS that is greater than the remaining dimensions. Thus, the expander  110 ″ tends to expand perpendicular to the ABS to a greater degree. The increase in thermal expansion, particularly coupled with the directionality of the thermal expansion, tends to cause the insulator  101 ″, the shields  102 ″ and  104 ″, and other nearby components of the transducer  100 ″ to protrude out toward the ABS. 
     Thus, the transducer  100 ″ may share the benefits of the transducers  100  and  100 ′. Because of the expander  110 ″ the thermally induced protrusion of the read transducer  100 ″ may be enhanced. The desired protrusion of the transducer  100 ″ may thus be achieved at a lower temperature, a greater protrusion may be achieved at the same temperature, and/or the desired protrusion may be attained despite variations in fabrication of the transducer  100 ″. Further, in this embodiment, a portion of the expander  110 ″ overlaps the heater  108 ″ in both the track width direction (as seen from the ABS) and perpendicular to the ABS. Thus, in addition to the benefits of the transducer  100 , the efficiency of heat transfer between the heater  108 ″ and the expander  110 ″ may be improved. In addition, because the expander  110 ″ can provide the desired protrusion at lower temperatures, the heater  108 ″ may be placed further from the sensor  106 ″. Thus, the sensor  106 ″ may be better protected from damage. 
       FIG. 5  depicts an exemplary embodiment of a portion of the magnetic head  80 . More specifically, a write transducer  150  is shown in  FIG. 5 . For simplicity, any other components of the head  80  are omitted and the media  60  is not shown in  FIG. 5 . For clarity,  FIG. 5  is not drawn to scale. Referring to  FIGS. 1 and 5 , the write transducer  150  is also described in the context of particular components and layers. However, in some embodiments, such layers may include sub-layer(s). In addition, some components may be moved, omitted, or combined with other components. 
     The write transducer  150  is used in writing to the media  60 . The write transducer  150  is shown as including a first pole  152 , auxiliary pole  154 , main pole  156 , write gap  166 , coils  160  and  162 , return shield  164 , heater  170  and expander  180 . However, in another embodiment, the write transducer  150  may include other and/or different components. For example, in other embodiments, the write transducer  150  may be an energy assisted magnetic recording (EAMR) transducer including optics for directing light energy toward a media for heating. In addition, one or more portions of the write transducer  150  might be omitted in various embodiments. 
     The heater  170  and expander  180  reside in an insulating layer  151  that insulates the turns of the coil  160 . However, in other embodiments, the heater  170  and/or the expander  180  may be located elsewhere. For example, the heater  170  and/or expander  180  might reside in the insulator adjoining the other coil  162 , on the other side of the pole  154 . Although the heater  170  and expander  180  are shown at particular locations in  FIGS. 1 and 5 , in other embodiments, these components  170  and  180  may be located elsewhere. 
     The heater  170  and expander  180  are analogous to the heater  108 / 108 ′/ 108 ″ and expander  110 / 110 ′/ 110 ″. Thus, the heater  170  is used to generate heat, which causes a local protrusion of the write transducer  150 . The expander  180  is proximate to the heater  170 . The expander  180  is desired to be nonmagnetic to prevent interference with operation of the write transducer  150 . In the embodiment shown, the expander  180  is between the heater  170  and the ABS. However, in other embodiments, at least a portion of the expander overlaps the heater  170 . In the embodiment shown, the expander  180  is recessed from the ABS. Thus, any issues due to corrosion may be mitigated or avoided. However, in other embodiments, the expander  180  may extend to the ABS. The CTE of the expander  180  is larger than the CTE of the insulator  151  surrounding the expander  180 . Thus, the expander  180  increases in size to a greater degree than the surrounding insulator  151  for the same temperature change. The CTE of the expander  180  may be at least twice the CTE of the insulator  151 . In some embodiments, the CTE of the expander  180  is at least three times the CTE of the insulator  151 . In some embodiments, the expander  180  may be a metal, such as copper having a CTE on the order of 16.5×10 −6 /K. Other materials including nonmetals may be used. However, metals may be preferred to improve the response time of the expander  180 . 
     The expander  180  is configured to improve the ability of the heater  170  to cause a protrusion of the write transducer  150  at the ABS. Thus, the CTE of the expander  180  is greater than the surrounding insulator  151 . In addition, the geometry of the expander  180  may be configured such that the change in size of the expander  180  due to heating by the heater  170  may be directional in nature. Thus, the expander  180  may be made relatively thin in the down track direction (vertically in  FIG. 5 ). The expander  180  may have a length perpendicular to the ABS that is at least twice the width in the track width direction (perpendicular to the plane of the page in  FIG. 5 ). Thus, the aspect ratio of the expander  180  may be at least two. In some embodiments, the aspect ratio of the expander  180  is at least five. The higher aspect ratio translates to a preferred direction of expansion: perpendicular to the ABS. Further, the expander  180  may be configured to overlap the active portion of the heater  170  in the track width direction. Thus, the width of the expander  180  in the track width direction may be at least as large as the width of the active portion of the heater  170  in the track width direction. Further, as viewed from the ABS, the expander  180  may be directly in front of, directly above, or directly below the active portion of the heater  170 . Thus, the expander  180  tends to overlap the active region of the heater in the track width direction. Thus, the expander  180  and heater  170  may be configured in an analogous manner to the expander  110 / 110 ′/ 110 ″ and heater  108 / 108 ′/ 108 ″ depicted in  FIGS. 2-4 . 
     In operation, the heater  170  generates heat. Both the insulator  151  and the expander  180  experience an increase in temperature and, therefore, size. However, because the expander  180  has a CTE that is greater than that of the insulator  151 , the expander  180  protrudes to a greater degree than the insulator  151 . Further, the expander  180  may have a length perpendicular to the ABS that is greater than the remaining dimensions. Thus, the change in length of the expander  180  is preferentially in the direction perpendicular to the ABS. The increase in thermal expansion, particularly coupled with the directionality of the thermal expansion, tends to cause the insulator  151 , the pole  156 , and other nearby components of the transducer  150  to protrude out toward the ABS. Thus, the expander  180  may enhance the thermally induced protrusion of the write transducer  150 . The desired protrusion of the transducer  150  may thus be achieved at a lower temperature, a greater protrusion may be achieved at the same temperature, and/or the desired protrusion may be attained despite variations in fabrication of the transducer  150 . 
       FIG. 6  depicts a perspective view of an exemplary embodiment of a portion of the magnetic head  80 . More specifically, a write transducer  150 ′ is shown in  FIG. 6 . For simplicity, any other components of the head  80  are omitted and the media  60  is not shown in  FIG. 6 . For clarity,  FIG. 6  is not drawn to scale. Referring to  FIGS. 1 and 6 , the write transducer  150 ′ is also described in the context of particular components and layers. However, in some embodiments, such layers may include sub-layer(s). In addition, some components may be moved, omitted, or combined with other components. The transducer  150 ′ is analogous to the transducer  150 . Consequently, analogous components are labeled similarly. The transducer  150 ′ thus includes a first pole  152 ′, auxiliary pole  154 ′, main pole  156 ′, write gap  166 ′, coils  160 ′ and 162′, return shield  164 ′, heater  170 ′ and expander  180 ′ analogous to a first pole  152 , auxiliary pole  154 , main pole  156 , write gap  166 , coils  160  and  162 , return shield  164 , heater  170  and expander  180 , respectively. The components  152 ′,  154 ′,  156 ′,  166 ′,  160 ′,  162 ′,  164 ′,  170 ′ and  180 ′ thus have a similar structure and function to the components  152 ,  154 ,  156 ,  166 ,  160 ,  162 ,  164 ,  170  and  180 , respectively. In the embodiment shown, the expander  180 ′ overlaps the heater  170 ′ in the down track direction. The heater  170 ′ and expander  180 ′ again reside in the insulator  151 ′ that also adjoins the main pole  156 ′. However, in this embodiment, a portion of the expander  110 ″ overlaps the heater  108 ″ in both the track width direction (as seen from the ABS) and perpendicular to the ABS. 
     The heater  170 ′ and expander  180 ′ function in an analogous manner to the heater  170  and expander  180 . Thus, a current is driven through the heater  170 ′, which generates heat. The surrounding portions of the transducer  150 ′ including the expander  180 ′ experience an increase in temperature. Because it has a larger CTE, the expander  180 ′ changes size to a greater extent than the insulator  151 ′. Further, the expander  180 ′ may have a length perpendicular to the ABS that is greater than the remaining dimensions. Thus, the expander  180 ′ tends to expand perpendicular to the ABS to a larger extent. The increase in thermal expansion, particularly coupled with the directionality of the thermal expansion, tends to cause the insulator  151 ′, the pole  156 ′, and other nearby components of the transducer  150 ′ to protrude out toward the ABS. 
     Thus, the transducer  150 ′ may share the benefits of the transducer  150 . Because of the expander  180 ′ the thermally induced protrusion of the write transducer  150 ′ may be enhanced. The desired protrusion of the transducer  150 ′ may thus be achieved at a lower temperature, a greater protrusion may be achieved at the same temperature, and/or the desired protrusion may be attained despite variations in fabrication of the transducer  150 ′. 
     Thus, the head  80  may include a read transducer and/or a write transducer. One or both of the read transducer and write transducer in the head  80  may include an expander. Thus, the benefits of the read transducer  100 / 100 ′/ 100 ″ and/or the write transducer  150 / 150 ′ may be achieved. 
     For example,  FIG. 7  depicts a head  80 ′ that includes a read transducer  100 ′″ and a write transducer  150 ″ that are analogous to the read transducer  100 / 100 ′/ 100 ″ and write transducer  150 / 150 ′, respectively. The transducer  100 ′″ thus includes shields  102 ′″ and  104 ′″, insulators  101 ′″ and  103 ′″, read sensor  106 ′″, heater  108 ′″ and expander  110 ′″ that are analogous to shields  102 / 102 ′/ 102 ″ and  104 / 104 ′/ 104 ″, insulators  101 / 101 ′/ 101 ″ and  103 / 103 ′/ 103 ″, read sensor  106 / 106 ′/ 106 ″, heater  108 / 108 ′/ 108 ″, and expander  110 / 110 ′/ 110 ″, respectively. The components  101 ′″,  102 ′″,  103 ′″,  104 ′″,  106 ′″,  108 ′″, and  110 ′″ thus have a similar structure and function to the components  101 / 101 ′/ 101 ″,  102 / 102 ′/ 102 ″,  103 / 103 ′/ 103 ″,  104 / 104 ′/ 104 ″,  106 / 106 ′/ 106 ″,  108 / 108 ′/ 108 ″, and  110 / 110 ′/ 110 ″, respectively. Similarly, the transducer  150 ″ includes a first pole  152 ″, auxiliary pole  154 ″, main pole  156 ″, write gap  166 ″, coils  160 ″ and  162 ″, return shield  164 ″, heater  170 ″ and expander  180 ″ analogous to a first pole  152 / 152 ′, auxiliary pole  154 / 154 ′, main pole  156 / 156 ′, write gap  166 / 166 ′, coils  160 / 160 ′ and  162 / 162 ′, return shield  164 / 164 ′, heater  170 / 170 ′ and expander  180 / 180 ′, respectively. The components  152 ″,  154 ″,  156 ″,  166 ″,  160 ″,  162 ″,  164 ″,  170 ″ and  180 ″ thus have a similar structure and function to the components  152 / 152 ′,  154 / 154 ′,  156 / 156 ′,  166 / 166 ,  160 / 160 ′,  162 / 162 ′,  164 / 164 ′,  170 / 170 ′ and  180 / 180 ′, respectively. 
     The head  80 ′ may thus share the benefits of both the read transducer  100 / 100 ′/ 100 ″ and the write transducer  150 / 150 ′. Because of the expander  180 ″ the thermally induced protrusion of the write transducer  150 ″ may be enhanced. The desired protrusion of the transducer  150 ″ may thus be achieved at a lower temperature, a greater protrusion may be achieved at the same temperature, and/or the desired protrusion may be attained despite variations in fabrication of the transducer  150 ″. Similarly, because of the expander  110 ′″, the thermally induced protrusion of the read transducer  100 ′″ of the read transducer  100 ′″ may be enhanced. The desired protrusion of the transducer  100 ′″ may thus be achieved at a lower temperature, a greater protrusion may be achieved at the same temperature, and/or the desired protrusion may be attained despite variations in fabrication of the transducer  100 ″. Further, the heater  108 ′″ may be placed further from the read sensor  106 ′″, reducing the probability the read sensor  106 ′″ will be damaged by the heater  108 ′″. 
       FIG. 8  depicts an exemplary embodiment of a method  200  for providing a read transducer that utilizes an expander. The method  200  is described in connection with the read transducer  100 . However, the method  200  may be used in connection with read transducers  100 ′,  100 ″ and/or other analogous read transducers that use an expander such as the expander  110 ,  110 ′, and  110 ″. Further, although depicted as a flow of single steps, the steps of the method  200  may be performed in parallel and/or continuously. In addition, the steps of the method  200  may include substeps, may be combined, may be performed in another order and/or may be interleaved. 
     The read sensor  106  is provided, via step  202 . Step  202  may include depositing the layers for the read sensor  106  and defining the read sensor. A nonmagnetic gap  103  may be provided, via step  204 . Alternatively, the gap  101  may be provided. Thus, in some embodiments, the shield  102  may be provided between steps  202  and  204 . The heater  108  is provided, via step  206 . The expander  110  is also provided, via step  208 . Note that steps  204 ,  206 , and  208  may be performed before step  202  for the transducer  100 , but after step  202  for the transducer  100 ′. Fabrication of the transducer  100  may then be completed. Thus, the benefits of the transducer  100 ,  100 ′,  100 ″, and/or  100 ′″ may be achieved. 
       FIG. 9  depicts an exemplary embodiment of a method  210  for providing a write transducer that utilizes an expander. The method  210  is described in connection with the write transducer  150 . However, the method  210  may be used in connection with read transducers  150 ′ and/or other analogous read transducers that use an expander such as the expander  180  and  180 ′. Further, although depicted as a flow of single steps, the steps of the method  210  may be performed in parallel and/or continuously. In addition, the steps of the method  210  may include substeps, may be combined, may be performed in another order and/or may be interleaved. 
     The main pole  156  is provided, via step  212 . Step  202  may include a number of patterning, deposition, and removal steps. The coil(s)  160  and  170  may then be provided, via step  214 . An insulator  151  may then be provided to insulate the turns of the coil  160 , via step  216 . The heater  180  is provided, via step  218 . The expander  180  is also provided, via step  220 . Fabrication of the transducer  150  may then be completed. Thus, the benefits of the transducer  150  and/or  150 ′″ may be achieved.