Low magnetostrictive material for reading sensors

Abstract

This disclosure relates throughout to a magnetic recording device including a readout sensor. The sensor includes: a first buffer layer; a first ferromagnetic (FM) layer comprising a single layer of Fe or FeSiAl, or a multilayer structure of Cr / Fe, NiAl / Fe, IrAl / Fe, FeSiAl / Fe, or Fe / FeSiAl; a first Co or CoFe interface layer; and a barrier layer. The sensor may also include a second Co or CoFe layer and a second FM layer. The second FM layer may comprise a single layer of Fe or FeSiAl, or a multilayer structure of Fe / Cr, Fe / NiAl, Fe / IrAl, FeSiAl / Fe, or Fe / FeSiAl. The second FM layer may be amorphous. Synthetic antiferromagnetic (SAF) pinning and an antiferromagnetic layer (AFM) may be disposed on the second FM layer. The sensor including one or more Fe-containing FM layers reduces coercivity and magnetostriction, and improves the stability of the readout sensor.

Description

Background Technology Technical Field

[0002] The embodiments disclosed herein relate to magnetic recording devices including a read head or read sensor.

[0003] Description of related fields

[0004] The amount of data processed by computers is increasing rapidly. To keep up with this increase, data storage devices, such as hard disk drives (HDDs), must improve their data storage and writing capabilities to handle the volume of data effectively. The magnetic recording media of storage devices requires higher recording densities to enhance the functionality and capabilities of computers and continue processing massive amounts of data.

[0005] To achieve higher recording densities in magnetic recording media (such as exceeding 2 Tbit / in) 2 The recording density reduces the width and spacing of data tracks, thus narrowing the corresponding magnetic recording bits encoded in each data track. Numerous proposals have attempted to achieve small readback elements in both the downtrack and crosstrack directions.

[0006] As linear density increases, there is a natural trade-off between resolution and signal-to-noise ratio (SNR), where either SNR or resolution is affected as the other increases. A similar issue arises as track spacing decreases and track count per inch (tpi) increases. Narrower devices required for reading narrow tracks typically have poorer SNR and areal density capacity (ADC) compared to wider devices.

[0007] Therefore, there is a need in the art for an improved read head that can read data with improved SNR and recording density. Summary of the Invention

[0008] This disclosure relates throughout to a magnetic recording device including a sensor. The sensor includes: a first buffer layer; a first ferromagnetic (FM) layer, the first buffer and the first FM layer comprising a monolayer of Fe or FeSiAl, or a multilayer structure of Cr / Fe, NiAl / Fe, IrAl / Fe, FeSiAl / Fe, or Fe / FeSiAl; a first Co or CoFe layer; and a barrier layer. The sensor may further include a second Co or CoFe layer, a second interface layer, and a second FM layer. The second FM layer may comprise a monolayer of Fe or FeSiAl, or a multilayer structure of Cr / Fe, NiAl / Fe, FeSiAl / Fe, or Fe / FeSiAl. The second FM layer may be amorphous. An optional synthetic antiferromagnetic (SAF) pinning layer is disposed on the second FM layer. The sensor including one or more Fe-containing FM layers reduces coercivity and magnetostriction, and improves stability.

[0009] In one embodiment, a sensor includes: a seed layer; a first buffer layer disposed on the seed layer; a first ferromagnetic (FM) layer disposed on the first buffer layer, the first buffer layer and the first FM layer comprising a single layer of Fe or FeSiAl, or a multilayer structure of Cr / Fe, NiAl / Fe, IrAl / Fe, FeSiAl / Fe or Fe / FeSiAl; a first Co-containing layer disposed on the FM layer, the first Co-containing layer comprising Co or CoFe; and a barrier layer disposed on the first Co-containing layer.

[0010] In another embodiment, a sensor includes: a seed layer; a first buffer layer disposed on the seed layer, the first buffer layer comprising NiAl, IrAl, or Cr; a first ferromagnetic (FM) layer disposed on the first buffer layer, the first FM layer comprising a monolayer of Fe or FeSiAl, or a multilayer structure of Fe, FeSiAl / Fe, or Fe / FeSiAl; a first Co-containing layer disposed on the FM layer, the first Co-containing layer comprising Co or CoFe; a barrier layer disposed on the first Co-containing layer; a second Co-containing layer disposed on the barrier layer, the second Co-containing layer comprising Co or CoFe, wherein the first Co-containing layer and the second Co-containing layer each have a thickness of about 3 Å to about 8 Å; and a second FM layer disposed on the second Co-containing layer.

[0011] In another embodiment, a sensor includes: a seed layer; a first buffer layer disposed on the seed layer, the first buffer layer comprising NiAl, IrAl, or Cr; a first ferromagnetic (FM) layer disposed on the first buffer layer, the first FM layer comprising a monolayer of Fe or FeSiAl, or a multilayer structure of FeSiAl / Fe or Fe / FeSiAl; a first Co-containing layer disposed on the FM layer, the first Co-containing layer comprising Co or CoFe; and an MgO layer disposed on... The first Co-containing layer; a second Co-containing layer disposed on the MgO layer, the second Co-containing layer comprising Co or CoFe, wherein the first Co-containing layer and the second Co-containing layer each have a thickness of about 3 Å to about 8 Å; a second FM layer disposed on the second Co-containing layer, the second FM layer comprising a monolayer of Fe or FeSiAl, or a multilayer structure of Fe / Cr, Fe / NiAl, Fe / IrAl, FeSiAl / Fe or Fe / FeSiAl; and a capping layer disposed on the second FM layer. Attached Figure Description

[0012] Therefore, a detailed understanding of the foregoing features of this disclosure, a more specific description of this disclosure, and the foregoing brief overview can be obtained by referring to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only typical embodiments of this disclosure and should therefore not be construed as limiting its scope, as this disclosure allows for other equally effective embodiments.

[0013] Figure 1 This is a schematic diagram of some embodiments of a magnetic media driver that includes a magnetic recording head with spintronics devices.

[0014] Figure 2 This is a partial cross-sectional view of some embodiments of a read / write head with spintronic devices.

[0015] Figure 3 A single free-layer structure of a readout sensor including a ferromagnetic (FM) layer is illustrated according to one embodiment.

[0016] Figure 4 An example is shown of a readout sensor comprising two FM layers according to one embodiment.

[0017] Figure 5A An example is a readout sensor comprising two FM layers according to another embodiment.

[0018] Figure 5B An example is given based on one implementation scheme. Figure 5A SAF pinning layer.

[0019] Figure 6 An example is shown of a readout sensor comprising two FM layers according to yet another embodiment.

[0020] Figure 7 An example is shown according to one implementation scheme. Figure 5A A graph showing the relationship between the magnetoresistive force (MR) and the resistive area (RA) of the sensor.

[0021] For ease of understanding, the same reference numerals are used where possible to denote the same elements common in the accompanying drawings. It is conceivable that elements disclosed in one embodiment may be advantageously used in other embodiments without specific description. Detailed Implementation

[0022] In the following text, reference is made to embodiments of this disclosure. However, it should be understood that this disclosure is not limited to the specifically described embodiments. Rather, any combination of the following features and elements (whether or not related to different embodiments) is contemplated to achieve and practice this disclosure. Furthermore, while embodiments of this disclosure may achieve advantages over other possible solutions and / or over the prior art, whether a particular advantage is achieved by a given embodiment is not a limitation of this disclosure. Therefore, the following aspects, features, embodiments, and advantages are merely illustrative and should not be considered as elements or limitations of the appended claims unless expressly stated in the claims. Similarly, reference to “this disclosure” should not be construed as a generalization of any inventive subject matter disclosed herein and should not be considered as elements or limitations of the appended claims unless expressly stated in the claims.

[0023] This disclosure relates throughout to magnetic recording devices including sensors. One sensor includes: a first buffer layer; a first ferromagnetic (FM) layer comprising a monolayer of Fe or FeSiAl, or a multilayer structure of Cr / Fe, NiAl / Fe, IrAl / Fe, FeSiAl / Fe, or Fe / FeSiAl; a first Co or CoFe layer; and a barrier layer. The sensor may further include a second Co or CoFe layer, a second interface layer, and a second FM layer. The second FM layer may comprise a monolayer of Fe or FeSiAl, or a multilayer structure of Fe / Cr, Fe / NiAl, Fe / IrAl, FeSiAl / Fe, or Fe / FeSiAl. The second FM layer may be amorphous and contain CoB, CoFeB, or CoFeTaB. A synthetic antiferromagnetic (SAF) pinning layer is disposed on the second FM layer. The sensor including one or more Fe-containing FM layers reduces coercivity and magnetostriction, and improves stability.

[0024] Figure 1 This is a schematic diagram of some embodiments of a magnetic media drive 100, which includes a magnetic recording head having a SOT, tunnel magnetoresistive (TMR), or magnetic tunnel junction (MTJ) device. Such magnetic media drives can be a single drive or include multiple drives. For illustration, a single disk drive 100 is shown according to some embodiments. As shown, at least one rotatable disk 112 is supported on a spindle 114 and rotated by a drive motor 118. Magnetic recording on each disk 112 is in the form of any suitable pattern of data tracks, such as a toroidal pattern of concentric data tracks (not shown) on disk 112.

[0025] At least one slider 113 is positioned near the disk 112, and each slider 113 supports one or more head assemblies 121 including SOT devices. As the disk 112 rotates, the sliders 113 move radially in and out above the disk surface 122, allowing the head assemblies 121 to access different tracks of the disk 112 for writing desired data. Each slider 113 is attached to an actuator arm 119 via a suspension 115. The suspension 115 provides a slight spring force that biases the slider 113 toward the disk surface 122. Each actuator arm 119 is attached to an actuator device 127. Figure 2 The actuator component 127 shown may be a voice coil motor (VCM). The VCM includes a coil capable of moving within a fixed magnetic field, the direction and speed of which the coil moves are controlled by a motor current signal supplied by a control unit 129.

[0026] During operation of the disk drive 100, the rotation of the disk 112 creates an air bearing between the slider 113 and the disk surface 122, which applies an upward force or lift to the slider 113. Thus, during normal operation, the air bearing counteracts the slight spring force of the suspension 115 and supports the slider 113 away from and slightly above the disk surface 122 with a small, substantially constant gap.

[0027] Various components of the disk drive 100 are operated by control signals (such as access control signals and internal clock signals) generated by the control unit 129. The control unit 129 typically includes logic control circuitry, storage components, and a microprocessor. The control unit 129 generates control signals that control various system operations, such as drive motor control signals on line 123 and head positioning and seek control signals on line 128. The control signals on line 128 provide a desired current distribution to optimally move and position the slider 113 onto the desired data track on the disk 112. Write and read signals are transmitted through the recording channel 125 to and from the write and read heads on component 121.

[0028] The above description of typical magnetic media drivers and Figure 1 The accompanying illustrations are for illustrative purposes only. It should be apparent that a magnetic media drive may contain a large number of media or disks and actuators, and each actuator may support multiple sliders.

[0029] It should be understood that the embodiments discussed herein are applicable to data storage devices such as hard disk drives (HDDs) and tape drives such as tape embedded drives (TEDs) or pluggable tape media drives. An example TED is described in a co-pending patent application, U.S. Patent Application No. 16 / 365,034, filed March 31, 2019, entitled “Tape Embedded Drive,” which is assigned to the same assignee as this application and is incorporated herein by reference. Therefore, any references to HDDs or tape drives in the detailed description are for illustrative purposes only and are not intended to limit this disclosure unless expressly asserted. For example, references to disk media in HDD embodiments are provided by way of example only, and tape media may be used instead in tape drive embodiments. Furthermore, references to magnetic recording devices or data storage devices, or claims relating to magnetic recording devices or data storage devices, are intended to include at least both HDDs and tape drives unless an HDD or tape drive device is expressly asserted. Additionally, the various embodiments disclosed herein can generally be used as part of a magnetic field sensor beyond magnetic sensing applications in data storage devices.

[0030] Figure 2 This is a partial cross-sectional side view of some embodiments of a read / write head 200 having an SOT, TMR, or MTJ device. The read / write head 200 faces the magnetic medium 112. The read / write head 200 may correspond to... Figure 1 The described head assembly 121. The read / write head 200 includes a media-facing surface (MFS) 212 (such as a gas-bearing surface) facing the disk 112, the write head 210, and the magnetic read head 211. Figure 2 As shown, the magnetic medium 112 moves past the write head 210 in the direction indicated by arrow 232, and the read / write head 200 moves in the direction indicated by arrow 234.

[0031] In some embodiments, the magnetic read head 211 is a magnetoresistive (MR) read head having an MR sensing element 204 located between MR shields S1 and S2. In other embodiments, the magnetic read head 211 is an MTJ read head including a magnetic tunnel junction (MTJ) sensing device 204 disposed between MR shields S1 and S2. The magnetic field of adjacent magnetized regions in the disk 112 can be detected as a recording bit by the MR (MTJ) sensing element 204.

[0032] The write head 210 includes a center or master electrode 220, a front shield 206, a rear shield 240, an optional auxiliary write element 250, and a coil 218 that activates the master electrode 220. The coil 218 may have a "pancake" shape, rather than... Figure 2The illustrated "spiral" structure, a "pancake-shaped" structure, is wound around the back contact between the master electrode 220 and the tail shield 240. For example, when included to achieve, for example, microwave-assisted magnetic recording (MAMR) effects, an auxiliary writing element 250 is formed in the gap 254 between the master electrode 220 and the tail shield 240. For example, the auxiliary writing element 250 may be a spin torque oscillator (STO) device or a conductive stack. In some embodiments, the read / write head 200 further includes a mechanism (not shown) for supporting heat-assisted magnetic recording (HAMR), which may include a waveguide coupled to a light source and a near-field transducer (NFT) placed adjacent to the master electrode 220 and coupled to the waveguide to convert the transmitted light into heated points on the medium.

[0033] The main electrode 220 includes a tail cone 242 and a front cone 244. The tail cone 242 extends from a recessed location in the MFS 212. The front cone 244 extends from a recessed location in the MFS 212. The tail cone 242 and the front cone 244 may have the same taper and the taper is measured relative to the longitudinal axis 260 of the main electrode 220. In some embodiments, the main electrode 220 does not include the tail cone 242 and the front cone 244. Instead, the main electrode 220 includes a tail side (not shown) and a front side (not shown), and the tail side and the front side are substantially parallel. The main electrode 220 may be a magnetic material, such as an FeCo alloy. The front shield 206 and the tail shield 240 may contain a magnetic material, such as a NiFe alloy.

[0034] Figures 3 to 6 Various readout sensors 300, 400, 500, and 600 according to various implementation schemes are illustrated. Each readout sensor 300, 400, 500, and 600 can be individually associated with... Figure 1 The magnetic head assembly 121 described herein, or a part thereof. Each readout sensor 300, 400, 500, 600 can individually correspond to... Figure 2 The read / write head 200 described herein, or a part thereof, such as magnetic read head 211, is used. Various aspects of the read sensors 300, 400, 500, and 600 can be combined with each other.

[0035] Figure 3A free-layer structure 300 of a readout sensor including a ferromagnetic (FM) layer 306 is illustrated according to one embodiment. The readout sensor 300 includes: a seed layer 302; a buffer layer 304 disposed on the seed layer 302; an FM layer 306 disposed on the buffer layer 304; a Co-containing interlayer 310 disposed on the FM layer 306; a barrier layer 312 disposed on the Co-containing interlayer 310; and a cover layer 314 disposed on the barrier layer 312.

[0036] The seed layer 302 comprises RuAl and has a thickness of about 25 Å to about 35 Å (such as about 30 Å) in the y-direction. The buffer layer 304 comprises NiAl, IrAl, or Cr and has a thickness of about 5 Å to about 10 Å in the y-direction. The buffer layer 304 helps improve the magnetic properties of the sensor and helps reduce the coercivity of the sensor 300. The barrier layer 312 comprises MgO and has a thickness of about 5 Å to about 10 Å in the y-direction. The capping layer 314 comprises RuAl, Ru, or a combination thereof in multiple layers and has a thickness of about 60 Å in the y-direction.

[0037] The Co-containing interlayer 310 contains Co or CoFe and has a thickness of about 3 Å to about 8 Å (such as about 5 Å) in the y-direction. The Co-containing interlayer 310 prevents the introduction of vertical anisotropy between the FM layer 306 and the barrier layer 312 and improves interfacial spin polarization. The FM layer 306 comprises a single-layer or multi-layer structure of Fe, FeSiAl, Fe / FeSiAl, or combinations thereof.

[0038] For example, the buffer layer 304 having the FM layer 306 comprises Cr / Fe, NiAl / Fe, IrAl / Fe, Cr / FeSiAl, NiAl / FeSiAl, IrAl / FeSiAl, Cr / FeSiAl / Fe, NiAl / FeSiAl / Fe, IrAl / FeSiAl / Fe, Cr / Fe / FeSiAl, NiAl / Fe / FeSiAl, or IrAl / Fe / FeSiAl, where " / " indicates a single sublayer of a multilayer structure. The dashed line indicates that the FM layer 306 may optionally be a multilayer structure. The FM layer 306 has a total thickness of about 40 Å to about 60 Å (such as about 50 Å) in the y-direction. When the FM layer 306 is a multilayer structure (such as FeSiAl / Fe), the Fe sublayer has a thickness of about 10 Å to about 20 Å in the y-direction. The FM layer 306, comprising Fe as a single layer or multilayer structure, reduces coercivity and magnetostriction (Ms), while improving the magnetoresistance (MR) and stability of the sensor. For example, the coercivity is between about 3 Oe and about 6 Oe, and the Ms is between about 1 ppm and about 2.6 ppm. The Fe-containing FM layer 306 further helps to reduce any defects introduced into the barrier layer 312.

[0039] The low-resistivity region (RA) with minimal defects in the barrier layer 312 (e.g., MgO) helps ensure the reliability of readout sensors with high areal density capabilities. Previously, structures employing CoFe (as an FM layer) with a RuAl seed layer were developed to provide textured templates for larger grain sizes and the growth of boron-free barrier layers (e.g., MgO). However, the magnetostriction and saturation magnetization of the CoFe-based free layer exceed those of the preferred amorphous CoB structure in some applications, potentially impacting the signal-to-noise ratio (SNR) and stability of the readout sensor. While an Fe-containing FM layer would result in reduced magnetostriction, it could introduce higher coercivity and a shallow saturation transition, as well as potential magnetoresistance degradation, compared to a Co-based FM layer. Therefore, the buffer layer 304 helps restore the low Hc of the FM layer, and as noted above, the Co-containing interlayer 310 prevents the introduction of vertical anisotropy between the FM layer 306 and the barrier layer 312 and improves interfacial spin polarization. The combination of these layers addresses the identified problems and provides improved overall sensor performance.

[0040] Figure 4An example of a readout sensor 400 comprising two FM layers 306, 406 according to one embodiment is illustrated. The readout sensor 400 includes: a seed layer 302; a first buffer layer 304 disposed on the seed layer 302; a first FM layer 306 disposed on the first buffer layer 304; a first Co- or CoFe-containing interlayer 310 disposed on the first FM layer 306; a barrier layer 312 disposed on the first Co-containing interlayer 310; a second Co- or CoFe-containing interlayer 410 disposed on the barrier layer 312; a second FM layer 406 disposed on the second Co- or CoFe-containing interlayer 410; a second buffer layer 404 disposed on the second FM layer 406; and a cover layer 314 disposed on the second buffer layer 404. The second Co-containing interlayer 410 improves the texture of the second FM layer 406 and improves the interface spin polarization.

[0041] The second Co-containing interlayer 410 contains Co or CoFe and has a thickness of about 3 Å to about 8 Å (such as about 5 Å) in the y-direction. The second buffer layer 404 contains the same material as the first buffer layer 304 and has the same thickness range as the first buffer layer. The second FM layer 406 contains Fe / Cr, Fe / NiAl, Fe / IrAl, FeSiAl, FeSiAl / Fe, or Fe / FeSiAl and has the same thickness range as the first FM layer 306. Therefore, the second FM layer 406 containing Fe (as a single-layer or multi-layer structure) further reduces coercivity and Ms, while improving the stability of the sensor.

[0042] Figure 5A An example is illustrated of a readout sensor 500 comprising two FM layers 306, 406 according to another embodiment. The readout sensor 500 is similar to... Figure 4The readout sensor 400; however, the readout sensor 500 includes a synthetic antiferromagnetic (SAF) pinning and antiferromagnetic (AFM) layer 516 instead of a second buffer layer 404. The readout sensor 500 includes: a seed layer 302; a buffer layer 304 disposed on the seed layer 302; a first FM layer 306 disposed on the buffer layer 304; a first Co-containing interlayer 310 disposed on the first FM layer 306; a barrier layer 312 disposed on the first Co-containing interlayer 310; a second Co-containing interlayer 410 disposed on the barrier layer 312; a second FM layer 406 disposed on the second Co-containing interlayer 410; a SAF pinning layer 516 disposed on the second FM layer 406; and a cover layer 314 disposed on the SAF pinning layer 516. SAF pinning layer 516 includes a Ru or RuAl spacer layer, a ferromagnetic layer, and an AFM layer, such as IrMn. Figure 5B As shown.

[0043] Figure 5B An example of a SAF pinning layer 516 according to one embodiment is illustrated. The SAF pinning layer 516 includes: a spacer layer 560; an FM layer structure 562 disposed on the spacer layer 560; and an AFM layer 564 disposed on the FM layer structure 562. The spacer layer 560 is disposed on a second FM layer 406, and a cover layer 314 is disposed on the AFM layer 564. The spacer layer 560 contains Ru or RuAl and has a thickness of about 4 Å to about 15 Å. The FM layer structure 562 contains Co, CoFe, CoFeBTa, or combinations thereof and has a thickness of about 50 Å. The AFM layer 564 contains IrMn and has a thickness of about 40 Å to about 60 Å.

[0044] Figure 6 An example is illustrated of a readout sensor 600 comprising two FM layers 306, 406 according to yet another embodiment. The readout sensor 600 is similar to... Figure 4The readout sensor 400; however, the second FM layer 604 is amorphous. The readout sensor 500 includes: a seed layer 302; a first buffer layer 304 disposed on the seed layer 302; a first FM layer 306 disposed on the first buffer layer 304; a first Co or CoFe sandwich layer 310 disposed on the first FM layer 306; a barrier layer 312 disposed on the first Co sandwich layer 310; a second Co or CoFe sandwich layer 410 disposed on the barrier layer 312; an amorphous FM layer 606 disposed on the second Co or CoFe sandwich layer 410; a second buffer layer 604 disposed on the amorphous FM layer 606; and a cover layer 314 disposed on the second buffer layer 604. The amorphous FM layer 606 comprises CoB, CoFeB, CoHf, CoFeBTa, or combinations thereof as a multilayer and has a thickness of approximately 50 Å in the y-direction. The second buffer layer 606 may comprise CoHf.

[0045] Figure 7 An example is shown according to one implementation scheme. Figure 5A The graph 700 shows the relationship between the magnetoresistive force (MR) and the resistive area (RA) of sensor 500. Although graph 700 is based on sensor 500, graph 700 is similarly applicable to... Figure 3 , Figure 4 and Figure 6 Sensors 300, 400 and 600.

[0046] Line 702 represents the FeAlSi-containing FM layer 306; line 704 represents the FeAlSi / Fe-containing FM layer 306, wherein the FeAlSi sublayer has a thickness of approximately 40 Å and the Fe sublayer has a thickness of approximately 10 Å; line 706 represents the Fe / FeAlSi-containing FM layer 306, wherein the FeAlSi sublayer has a thickness of approximately 30 Å and the Fe sublayer has a thickness of approximately 20 Å; line 708 represents the FeAlSi / Fe-containing FM layer 306, wherein the FeAlSi sublayer has a thickness of approximately 30 Å and the Fe sublayer has a thickness of approximately 20 Å; and line 710 represents the FeAlSi / Fe-containing FM layer 306 with reduced barrier thickness, wherein the FeAlSi sublayer has a thickness of approximately 30 Å and the Fe sublayer has a thickness of approximately 20 Å. As shown in graph 700, each Fe-containing FM layer increases MR and areal density capacity (ACD) while reducing RA, thereby improving the sensor.

[0047] Therefore, readout sensors comprising one or more FM layers containing Fe (as a single or multilayer structure) reduce coercivity and Ms, while improving sensor stability and MR. The Fe-containing FM layer further helps to reduce any defects introduced by the barrier layer. Thus, the readout sensor exhibits improved stability and low resistive area (RA) without affecting SNR.

[0048] In one embodiment, a sensor includes: a seed layer; a first buffer layer disposed on the seed layer; a first ferromagnetic (FM) layer disposed on the first buffer layer, the first buffer layer comprising a single layer of Fe or FeSiAl, or a multilayer structure of Cr / Fe, NiAl / Fe, IrAl / Fe, FeSiAl / Fe, or Fe / FeSiAl; a first Co-containing layer disposed on the first FM layer, the first Co-containing layer comprising Co or CoFe; and a barrier layer disposed on the first Co-containing layer.

[0049] The sensor further includes a capping layer disposed on the barrier layer. The sensor also includes: a second Co-containing layer disposed on the barrier layer, the second Co-containing layer comprising Co or CoFe; and a second FM layer disposed on the second Co-containing layer, the second FM layer comprising Co or CoFe. The sensor further includes: a second buffer layer disposed on the second FM layer; and a capping layer disposed on the second buffer layer, wherein the second FM layer comprises a monolayer of Fe or FeSiAl, or a multilayer structure of Cr / Fe, NiAl / Fe, FeSiAl / Fe, or Fe / FeSiAl. The second FM layer comprises an amorphous material. The sensor further includes: a synthetic antiferromagnetic (SAF) pinning and antiferromagnetic (AFM) layer disposed on the second FM layer; and a capping layer disposed on the SAF pinning and AFM layer. The first FM layer comprises the FeSiAl monolayer. The first FM layer comprises a multilayer structure of Cr / Fe, NiAl / Fe, FeSiAl / Fe, or Fe / FeSiAl. A magnetic recording device includes this sensor.

[0050] In another embodiment, a sensor includes: a seed layer; a first buffer layer disposed on the seed layer, the first buffer layer comprising NiAl or Cr; a first ferromagnetic (FM) layer disposed on the first buffer layer, the first FM layer comprising a monolayer of Fe or FeSiAl, or a multilayer structure of Cr / Fe, NiAl / Fe, FeSiAl / Fe, or Fe / FeSiAl; a first Co-containing layer disposed on the first FM layer, the first Co-containing layer comprising Co or CoFe; a barrier layer disposed on the first Co-containing layer; a second Co-containing layer disposed on the barrier layer, the second Co-containing layer comprising Co or CoFe, wherein the first Co-containing layer and the second Co-containing layer each have a thickness of about 3 Å to about 8 Å; and a second FM layer disposed on the second Co-containing layer.

[0051] The second FM layer comprises a monolayer of Fe or FeSiAl, or a multilayer structure of Fe / Cr, Fe / NiAl, Fe / IrAl, FeSiAl / Fe, or Fe / FeSiAl. The second FM layer is an amorphous FM layer comprising CoB, CoHf, CoFeB, CoFeBTa, or combinations thereof. The sensor also includes a synthetic antiferromagnetic (SAF) pinning and antiferromagnetic (AFM) layer disposed on the second FM layer. The first FM layer has a thickness of approximately 40 Å to approximately 50 Å. The sensor also includes a second buffer layer disposed on the second FM layer, comprising NiAl, IrAl, or Cr. The second FM layer comprises a multilayer structure of Cr / Fe, NiAl / Fe, FeSiAl / Fe, or Fe / FeSiAl. The first FM layer comprises a monolayer of FeSiAl. The first FM layer comprises a multilayer structure of Cr / Fe, NiAl / Fe, FeSiAl / Fe, or Fe / FeSiAl. A magnetic recording device includes the sensor.

[0052] In another embodiment, a sensor includes: a seed layer; a first buffer layer disposed on the seed layer, the first buffer layer comprising NiAl or Cr; a first ferromagnetic (FM) layer disposed on the first buffer layer, the first FM layer comprising a monolayer of Fe or FeSiAl, or a multilayer structure of Cr / Fe, NiAl / Fe, FeSiAl / Fe, or Fe / FeSiAl; a first Co-containing layer disposed on the first FM layer, the first Co-containing layer comprising Co or CoFe; and an MgO layer, the MgO layer comprising Co or CoFe. An O layer is disposed on the first Co-containing layer; a second Co-containing layer is disposed on the MgO layer, the second Co-containing layer comprising Co or CoFe, wherein the first Co-containing layer and the second Co-containing layer each have a thickness of about 3 Å to about 8 Å; a second FM layer is disposed on the second Co-containing layer, the second FM layer comprising a monolayer of Fe or FeSiAl, or a multilayer structure of Cr / Fe, NiAl / Fe, IrAl / Fe, FeSiAl / Fe or Fe / FeSiAl; and a capping layer is disposed on the second FM layer.

[0053] The sensor further includes a second buffer layer disposed between the second FM layer and the capping layer, the second buffer layer comprising NiAl, IrAl, or Cr. The sensor also includes a synthetic antiferromagnetic (SAF) pinning and antiferromagnetic (AFM) layer disposed on the second FM layer. The seed layer comprises RuAl. The first FM layer and the second FM layer each individually have a thickness of about 40 Å to about 50 Å. The first FM layer and the second FM layer each individually comprise a FeSiAl monolayer. The first FM layer and the second FM layer each individually comprise a Cr / Fe, NiAl / Fe, FeSiAl / Fe, or Fe / FeSiAl multilayer structure. A magnetic recording device includes this readout sensor.

[0054] While the foregoing describes embodiments of this disclosure, other and additional embodiments of this disclosure may be contemplated without departing from the basic scope of this disclosure, the scope of which is defined by the appended claims.

Claims

1. A sensor, the sensor comprising: Seed layer; A first buffer layer is disposed on the seed layer; The first ferromagnetic (FM) layer is disposed on the first buffer layer. The first FM layer includes a single layer of Fe or FeSiAl, or a multilayer structure of Cr / Fe, NiAl / Fe, FeSiAl / Fe or Fe / FeSiAl. A first Co-containing layer, disposed on the first FM layer, the first Co-containing layer comprising Co or CoFe; and A barrier layer is disposed on the first Co-containing layer.

2. The sensor according to claim 1, further comprising a cover layer disposed on the barrier layer.

3. The sensor according to claim 1, further comprising: A second Co-containing layer is disposed on the barrier layer, and the second Co-containing layer contains Co or CoFe; and The second FM layer is disposed on the second Co-containing layer.

4. The sensor according to claim 3, further comprising: A second buffer layer is disposed on the second FM layer; and A cover layer is disposed on the second buffer layer, wherein the second FM layer comprises a single layer of Fe or FeSiAl, or a multilayer structure of Cr / Fe, NiAl / Fe, IrAl / Fe, FeSiAl / Fe, or Fe / FeSiAl.

5. The sensor of claim 3, wherein the second FM layer comprises an amorphous material.

6. The sensor according to claim 3, further comprising: A synthetic antiferromagnetic (SAF) pinning and antiferromagnetic (AFM) layer is disposed on the second FM layer; and A cover layer is disposed on the SAF pinning and AFM layers.

7. The sensor of claim 1, wherein the first FM layer comprises the single layer of FeSiAl.

8. The sensor according to claim 1, wherein the first FM layer comprises the multilayer structure of Cr / Fe, NiAl / Fe, FeSiAl / Fe, or Fe / FeSiAl.

9. A magnetic recording device, the magnetic recording device comprising the sensor according to claim 1.

10. A sensor, the sensor comprising: Seed layer; A first buffer layer is disposed on the seed layer, and the first buffer layer comprises NiAl, IrAl or Cr; The first ferromagnetic (FM) layer is disposed on the first buffer layer. The first FM layer includes a single layer of Fe or FeSiAl, or a multilayer structure of FeSiAl / Fe or Fe / FeSiAl. A first Co-containing layer is disposed on the first FM layer, and the first Co-containing layer contains Co or CoFe; A barrier layer is disposed on the first Co-containing layer; A second Co-containing layer is disposed on the barrier layer, the second Co-containing layer comprising Co or CoFe, wherein the first Co-containing layer and the second Co-containing layer each have a thickness of about 3 Å to about 8 Å. and The second FM layer is disposed on the second Co-containing layer.

11. The sensor according to claim 10, wherein the second FM layer comprises a single layer of Fe or FeSiAl, or a multilayer structure of Fe / Cr, Fe / NiAl, Fe / IrAl, FeSiAl / Fe, or Fe / FeSiAl.

12. The sensor of claim 10, wherein the second FM layer is an amorphous FM layer comprising CoB, CoHf, CoFeB, CoFeBTa, or a combination thereof.

13. The sensor according to claim 10, further comprising a synthetic antiferromagnetic (SAF) pinning and an antiferromagnetic (AFM) layer disposed on the second FM layer.

14. The sensor of claim 10, wherein the first FM layer has a thickness of about 40 Å to about 50 Å.

15. The sensor according to claim 10, further comprising a second buffer layer disposed on the second FM layer, the second buffer layer comprising NiAl, IrAl or Cr.

16. The sensor of claim 10, wherein the second FM layer comprises the multilayer structure of Cr / Fe, NiAl / Fe, FeSiAl / Fe, or Fe / FeSiAl.

17. The sensor of claim 10, wherein the first FM layer comprises the monolayer of FeSiAl.

18. The sensor of claim 10, wherein the first FM layer comprises the multilayer structure of Cr / Fe, NiAl / Fe, FeSiAl / Fe, or Fe / FeSiAl.

19. A magnetic recording device, the magnetic recording device comprising the sensor according to claim 10.

20. A sensor, the sensor comprising: Seed layer; A first buffer layer is disposed on the seed layer, and the first buffer layer comprises NiAl, IrAl or Cr; The first ferromagnetic (FM) layer is disposed on the first buffer layer. The first FM layer includes a single layer of Fe or FeSiAl, or a multilayer structure of Cr / Fe, NiAl / Fe, FeSiAl / Fe or Fe / FeSiAl. A first Co-containing layer is disposed on the first FM layer, and the first Co-containing layer contains Co or CoFe; An MgO layer is disposed on the first Co-containing layer; A second Co-containing layer is disposed on the MgO layer, the second Co-containing layer comprising Co or CoFe, wherein the first Co-containing layer and the second Co-containing layer each have a thickness of about 3 Å to about 8 Å. The second FM layer is disposed on the second Co-containing layer, and the second FM layer comprises a single layer of Fe or FeSiAl, or a multilayer structure of Cr / Fe, NiAl / Fe, IrAl / Fe, FeSiAl / Fe, or Fe / FeSiAl; and A cover layer is disposed on the second FM layer.

21. The sensor of claim 20, further comprising a second buffer layer disposed between the second FM layer and the cover layer, the second buffer layer comprising NiAl, IrAl or Cr.

22. The sensor according to claim 20, further comprising a synthetic antiferromagnetic (SAF) pinning and an antiferromagnetic (AFM) layer disposed on the second FM layer.

23. The sensor of claim 20, wherein the seed layer comprises RuAl.

24. The sensor of claim 20, wherein the first FM layer and the second FM layer each individually have a thickness of about 40 Å to about 50 Å.

25. The sensor of claim 20, wherein the first FM layer and the second FM layer each individually comprise the single layer of FeSiAl.

26. The sensor of claim 20, wherein the first FM layer and the second FM layer each individually comprise the multilayer structure of Cr / Fe, NiAl / Fe, FeSiAl / Fe, or Fe / FeSiAl.

27. A magnetic recording device, the magnetic recording device comprising the sensor according to claim 20.

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