Abstract: The present invention relates to a method of synthesizing an ordered magnetic alloy comprising obtaining a substrate and performing sequential sputter deposition of multiple atomic monolayers of the magnetic alloy.

Abstract: Magnetic tunnel junctions are constructed from a MgO or Mg—ZnO tunnel barrier and amorphous magnetic layers in proximity with, and on respective sides of, the tunnel barrier. The amorphous magnetic layer preferably includes Co and at least one additional element selected to make the layer amorphous, such as boron. Magnetic tunnel junctions formed from the amorphous magnetic layers and the tunnel barrier have tunneling magnetoresistance values of up to 200% or more.

Abstract: In general, the invention is directed to techniques for reducing the amount of switching current that is utilized within a magnetic storage (e.g., MRAM) device. An example apparatus includes a fixed magnetic layer that provides a fixed direction of magnetization, an exchange-coupled magnetic multi-layer structure, and a non-magnetic layer placed between the fixed magnetic layer and the exchange-coupled magnetic multi-layer structure. The exchange-coupled magnetic multi-layer structure includes a recording layer configured to record information and an assisting layer having a lower anisotropy than the recording layer. The exchange coupling between the recording and assisting layers is operable to switch a magnetization direction of the recording layer. In some cases, the exchange-coupled magnetic multi-layer structure may further include a spacer separating the recording and assisting layers and configured to weaken an exchange coupling between the recording and assisting layers.

Abstract: The aspects of the present invention provide a magnetic recording head, a method for manufacturing a magnetic recording head, and a magnetic recording head drive. The magnetic recording head includes a substrate and a first magnetic device connected to the substrate. The magnetic recording head also includes a second magnetic device connected to the first magnetic device. The first magnetic device is aligned with the second magnetic device. The first and second magnetic devices are supported by the same side of the substrate.

Abstract: A perpendicular magnetic recording medium comprising a substrate, a soft underlayer, a seed layer, a non-magnetic FCC NiW alloy underlayer, a non-magnetic HCP underlayer, and a magnetic layer. We have discovered that the combination of a seed layer comprising Ta and a NiW alloy underlayer uniquely improves media recording performance and thermal stability by achieving excellent coercivity of the thin bottom magnetic recording layer and narrow C axis orientation distribution.

Abstract: Disclosed is a magnetoresistive random access memory (“MRAM”) device comprising a plurality of layers on a substrate. The plurality of layers comprises pinning layers, flipping layers, and at least one insulating layer between the pinning layers and the flipping layers. An eddy current side wall encapsulates at least the pinning layers of the plurality of layers. The eddy current side wall comprises a grain insulating layer for electrical insulation, and a magnetic barrier layer for magnetic isolation.

Abstract: In a perpendicular magnetic recording medium in which at least a soft magnetic underlayer, an orientation control layer, a magnetic recording layer and a protective layer are formed on a non-magnetic substrate in order from the bottom, the orientation control layer has a laminated structure of two or more layers including an intermediate layer and a seed layer which is disposed closer to the non-magnetic substrate than the intermediate layer. The seed layer includes two or more kinds of elements having a face-centered cubic structure, has face-centered cubic (111) plane crystals oriented in a direction perpendicular to a substrate surface, and has a pseudo-hexagonal structure.

Abstract: A magnetic tunneling element is constructed from a MgO or Mg—ZnO tunnel barrier and an amorphous magnetic layer in proximity with the tunnel barrier. The amorphous magnetic layer includes Co and at least one additional element selected to make the layer amorphous. Magnetic tunnel junctions formed from the amorphous magnetic layer, the tunnel barrier, and an additional ferromagnetic layer have tunneling magnetoresistance values of up to 200% or more.

Abstract: A perpendicular magnetic recording medium having a dual-layer magnetic film is disclosed. The bottom layer is completely exchange decoupled, and the top layer contains a certain amount of exchange coupling optimized for recording performance. Preferably, the bottom magnetic layer contains stable oxide material (for example, TiO2) and other non-magnetic elements (for example, Cr). A method of manufacturing the media is also disclosed.

Abstract: A method of fabricating a discrete track magnetic recording media. A base layer is provided onto which repeating and alternating magnetic layer and non-magnetic layers are deposited. The thickness of the magnetic layer corresponds to the width of the track of the recording media. A cylindrical rod can be used as the base layer, such that the alternating magnetic and non-magnetic layers spiraling or concentric layers around the rod. The resulting media layer can be cut or sliced into individual magnetic media or used to imprint other media discs with the discrete pattern of the media layer.

Abstract: [PROBLEMS] To improve the track density by reducing the track edge noise and sharpening the boundaries of a recording magnetic field by blocking the recording magnetic field spreading outside the recording region in magnetic recording. [MEANS FOR SOLVING PROBLEMS] A magnetic recording medium (10) has a substrate (12) and a perpendicular magnetic recording layer (30) formed over the substrate (12). The perpendicular magnetic recording layer (30) has a granular layer (20) in which a magnetic signal is recorded and a continuous film layer (24) magnetically coupled to the granular layer (20).

Abstract: The invention relates to a perpendicular magnetic recording medium having a substrate and a seed layer comprising a Ni alloy.

Abstract: Encapsulated particles and methods for manufacturing encapsulated particles and structures are described. Such particles may have a length no greater than 40 nm, and include at least one material selected from the group consisting of ferromagnetic materials and ferrimagnetic materials. A polymeric encapsulant surrounds the particle, the polymeric encapsulant including a phase-separated block copolymer including a glassy first phase and a rubbery second phase, the glassy first phase positioned between the particle and the second rubbery phase. The glassy first phase includes a hydrophobic copolymer having a glass transition temperature of at least 50° C. The rubbery second phase includes a polymer having at least one of (i) a glass transition temperature of no greater than 30° C., and (ii) a tan delta peak maximum of no greater than 30° C. Other embodiments are described and claimed.

Abstract: Methods of fabricating perpendicular write elements for perpendicular magnetic recording heads are discussed. In write element fabrication, write poles are fabricated according to one of many desired methods. The write poles during fabrication are typically covered by a hard mask and a photolithographic soft mask. According to the methods described herein, the soft mask is removed such as by chemical etching. The hard mask is then removed, such as by CMP and ion etching, to expose the write poles. Shield gap material may then be deposited on the write poles to define the shield gap between the write poles and the trailing shields. Trailing shield material may then be deposited on the shield gap material to form the trailing shields corresponding with the write poles.

Abstract: The invention relates to a magnetic recording medium having a solid lubricant film layer which is deposited by plasma-enhanced chemical vapor deposition. The solid lubricant film comprises a perfluoropolyether, which is formed by the polymerization of a perfluorocycloalkane.

Abstract: A perpendicular magnetic recording medium is manufactured having excellent thermal stability and recording performances across the entire disk surface. In one embodiment, the recording layer includes at least two layers deposited by using a reactive sputtering method under an oxygen-containing atmosphere at a deposition rate larger than the second recording layer which is formed on the first recording layer while depositing the first recording layer on the intermediate layer.

Abstract: A method for the production of a magnetic recording medium (30) includes the steps of depositing a magnetic layer or Co-containing magnetic layer (3) on at least one side of a nonmagnetic substrate (1) and partially implanting atoms into the magnetic layer or Co-containing magnetic layer to partially unmagnetize the magnetic layer or Co-containing magnetic layer, thereby forming nonmagnetic parts (4) and a magnetic recording pattern magnetically separated by the nonmagnetic parts and, in the case of the Co-containing magnetic layer, lowering Co (002) or Co (110) peak strength of a relevant part of the Co-containing magnetic layer as determined by the X-ray diffraction to ½ or less.

Abstract: MgO tunnel barriers are formed by depositing a thin layer of Mg on a suitable underlayer, and then directing oxygen and additional Mg towards the Mg layer. The oxygen reacts with the additional Mg and the Mg in the Mg layer to form a MgO tunnel barrier that enjoys excellent tunneling characteristics. The MgO tunnel barriers so formed may be used in magnetic tunnel junctions having tunneling magnetoresistance (TMR) values of greater than 100%. The highest TMR values are observed for junctions that have been annealed and that have a (100) crystallographic orientation.

Abstract: A magnetic recording medium for high-density recording, having a doped interlayer to preserve the uniformity and ordering of the magnetic nanoparticles in its recording layer. The interlayer is doped with a high electronegativity material. The dopant atoms in the interlayer interact with the ferromagnetic nanoparticles to promote the formation of a homogeneous, ordered monolayer of nanoparticles in the recording layer. In addition, the high electronegative property of the dopant atoms holds the nanoparticles in place during the subsequent annealing process to prevent sintering and disordering damage. In one embodiment, the dopant is a halogen or non-halogen material having a high electronegativity, which is not polymerized to the matrix material in the interlayer. The matrix material may be polymerized. An example of a doped interlayer is a fluorinated carbon film.

Abstract: A method of forming a CPP-GMR spin valve having a pinned layer with an AP2/coupling/AP1 configuration is disclosed wherein the AP2 portion is a FCC-like trilayer having a composition represented by CoZFe(100-Z)/Fe(100-X)TaX/CoZFe(100-Z) or CoZFe(100-Z)/FeYCo(100-Y)/CoZFe(100-Z) where x is 3 to 30 atomic %, y is 40 to 100 atomic %, and z is 75 to 100 atomic %. Preferably, z is 90 to provide a face centered cubic structure that minimizes electromigration. Optionally, the middle layer is comprised of an Fe rich alloy such as FeCr, FeV, FeW, FeZr, FeNb, FeHf, or FeMo. EM performance is improved significantly compared to a spin valve with a conventional AP2 Co50Fe50 or Co75Fe25 single layer. MR ratio is also increased and RA is maintained at an acceptable level. The coupling layer is preferably Ru and the AP1 layer may be comprised of a lamination of CoFe and Cu layers as in [CoFe/Cu]2/CoFe.

Abstract: A perpendicular magnetic recording medium and method thereof, includes a nonmagnetic substrate; a soft magnetic under layer; an intermediate layer; a bilayer magnetic recording layer; a protective layer; and a liquid lubricant layer. According to a following order, the soft magnetic under layer, the intermediate layer, the bilayer magnetic recording layer, the protective layer, and the liquid lubricant layer are sequentially stacked on the nonmagnetic substrate. The bilayer magnetic recording layer includes a first magnetic layer including a CoCr alloy crystalline film, and a second magnetic layer including a rare earth-transition metal alloy noncrystalline film.

Abstract: [Object] To achieve a high coercive force (Hc) and low-noise characteristics (high S/N ratio) through realization of both segregation of SiO2 and high perpendicular magnetic anisotropy by providing a two-layer structure having magnetic recording layers with different properties. [Solution] A magnetic disk for use in perpendicular magnetic recording, having at least an underlayer 5, a first magnetic recording layer 6, and a second magnetic recording layer 7 on a substrate in this order. The first magnetic recording layer 6 and the second magnetic recording layer 7 are each a ferromagnetic layer of a granular structure containing a nonmagnetic substance forming grain boundary portions between crystal grains containing at least Co (cobalt). Given that the content of the nonmagnetic substance in the first magnetic recording layer 6 is A mol % and the content of the nonmagnetic substance in the second magnetic recording layer 7 is B mol %, A>B.

Abstract: Perpendicular magnetic recording media and methods of fabricating perpendicular magnetic recording media are described. The perpendicular magnetic recording medium of one embodiment includes an interlayer, an underlayer, and a perpendicular magnetic recording layer. The interlayer is comprised of a Ni-alloy having the characteristics of being nonmagnetic and having an FCC structure. The alloying element for the Ni-alloy may comprise one of V or Cr, or may comprise one of V, Cr, or W. The concentration of the alloying element is set such that the concentration of the alloying element is high enough to make the Ni-alloy non-magnetic, while low enough to maintain an FCC structure for the Ni-alloy.

Abstract: Although dots and servo patterns are made of the same magnetic material, the dots have a relatively low coercive force so as to allow data deletion and rewrite by a magnetic head, whilst the servo patterns have a high coercive force compared with the coercive force of the dots. The coercive force of the servo patterns is strong enough so as to eliminate the influence of shape magnetic anisotropy.

Abstract: A method of making a current-perpendicular-to-the-plane giant magnetoresistive (CPP-GMR) sensor with a confined-current-path (CCP) layer uses an array of self-assembled ferritin protein molecules with inorganic cores to make the CCP layer in the sensor stack. In one embodiment, the ferritin molecules with cores of insulating oxide particles are deposited on an electrically conductive support layer and the ferritin molecules are dissolved, leaving an array of insulating oxide particles. An electrically conducting layer is deposited over the oxide particles and into the regions between the oxide particles to form the CCP layer. In another embodiment, the ferritin molecules with inorganic particles in their cores are deposited on an electrically insulating support layer and the ferritin molecules are dissolved, leaving an array of inorganic particles that function as an etch mask.

Abstract: This application relates to a new process for the application of thin layers of substantially pure spin transition molecular materials while maintaining the hysteresis properties of the material. The process makes it possible to obtain a dense uniform surface with very low roughness.

Abstract: In a method in the fabrication of a ferroelectric memory device comprising a memory layer sandwiched between first and second electrode sets, the memory layer as well as both electrode sets are each realized in the memory device by a suitable printing process.

Abstract: A high performance TMR sensor with a spacer including at least one Cu layer and one or more MgO layers is disclosed. Optionally, Cu may be replaced by one of Au, Zn, Ru, or Al. In addition, there may be a dopant such as Zn, Mn, Al, Cu, Ni, Cd, Cr, Ti, Zr, Hf, Ru, Mo, Nb, Co, or Fe in the MgO layer. In an alternative embodiment, the MgO layer may be replaced by other low band gap insulating or semiconductor materials. A resonant tunneling mechanism is believed to be responsible for achieving an ultra-low RA of <0.4 ?ohm-cm2 in combination with a MR of 14%, low magnetostriction, and a low Hin value of about 20 Oe. The Cu layer thickness is from 0.1 to 10 Angstroms and the MgO thickness is from 5 to 20 Angstroms in spacer configurations including Cu/MgO/Cu, MgO/Cu/MgO, Cu/MgO, MgO/Cu, Cu/MgO/Cu/MgO/Cu, and (Cu/MgO)n/Cu multilayers.

Abstract: Embodiments of the present invention provide a magnetic head having a read head of stable reading operation and with less magnetic fluctuation noise. According to one embodiment, a free layer has a structure comprising two ferromagnetic layers (a first free layer and a second free layer) that are coupled anti-ferromagnetically by way of a non-magnetic intermediate layer, in which the magnetization amount of the first free layer is set to larger than the magnetization amount of the second free layer. Further, the magnetic domains in the first free layer and the second free layer are stabilized simultaneously by increasing the distance between the second free layer and the magnetic domain control film to be more than the distance between the first free layer and the magnetic domain control film, thereby adjusting the magnetization amount of the magnetic domain control film.

Abstract: Aspects of the present embodiments are related to manufacturing methods of magnetic recording media. The manufacturing method of a magnetic recording medium includes a step of stacking a soft magnetic backing layer, an intermediate layer, a first recording layer having a perpendicular magnetic anisotropy, an exchange coupling force control layer including ruthenium, and a second recording layer having a perpendicular magnetic anisotropy on a substrate in order. A gas pressure of a process gas when the exchange coupling force control layer is being formed is higher than the gas pressure of the process gas when being normally used.

Abstract: A magnetic recording medium is formed by stacking in order, on a nonmagnetic base, at least an underlayer, magnetic recording layer, and protective layer. The magnetic recording layer includes a plurality of magnetic layers and an exchange-coupling control layer, and the magnetic recording medium is characterized in that a physical pattern is formed in the exchange-coupling control layer. The exchange-coupling control layer is located between the magnetic layers of the magnetic recording layer.

Abstract: In a manufacturing method of a perpendicular magnetic recording medium, a lower base layer is formed by depositing Ru or an Ru alloy on a soft magnetic underlayer in an inert gas atmosphere containing carbonized oxygen. An upper base layer is formed by depositing Ru or an Ru alloy on the lower base layer in an inert gas atmosphere. A magnetic layer serving as a recording layer is formed on the upper base layer.

Abstract: A method of making a hard disk drive platter comprises providing a substrate having first and second surfaces; arranging a strengthening layer including glassy metal on at least one of the first and second surfaces; and arranging at least one magnetic layer on at least one of the substrate and the strengthening layer.

Abstract: A method for producing a magnetic recording medium in which the noise of the magnetic recording medium is reduced and the thermal stability of the recorded magnetization is improved, while enabling easy writing to be carried out by a recording head, is disclosed. The magnetic recording medium of the present invention includes an underlayer having an hcp crystal structure and a magnetic layer produced by a multilayer lamination of Co/Pt or the like. The deposition rate of the underlayer is equal to or lower than 0.7 nm/second. The magnetic layer contains added silicon oxide at 1 to 10 mol %. The present method includes a step for subjecting the surface of the underlayer to Ar gas mixed with oxygen of a mass/flow rate ratio of 1% to 10% under a gas pressure of 0.1 to 10 Pa for 1 to 10 second(s). The magnetic recording medium may include an orientation control layer and a soft magnetic backing layer. Ku, Ku1, and Ku2 are controlled to provide both of thermal stability and easy writing.

Abstract: Embodiments of the present invention provide a perpendicular magnetic recording head including a coil having small resistance. According to one embodiment, a nonmagnetic insulating layer formed on a main magnetic pole and a magnetic yoke are etched to form a recessed portion. The thickness of a conductive layer is increased by the depth of the recessed portion in a process for forming the conductive layer of the upper coil on the recessed portion to reduce resistance of the coil. Simultaneously with the formation of the recessed portion, a part of a second layer of a connection tab is removed. Simultaneously with the formation of the conductive layer of the upper coil, a space in which the part of the second layer of the connection tab is removed is filled with the same material as that of the conductive layer to further reduce the resistance of the entire coil.

Abstract: A magneto-resistance effect element comprises: a magneto-resistance effect stack including an upper magnetic layer and a lower magnetic layer whose magnetization directions change in accordance with an external magnetic field, a non-magnetic intermediate layer sandwiched between the upper and lower magnetic layers; an upper shield electrode layer and a lower shield electrode layer which are provided to sandwich the magneto-resistance effect stack therebetween in the direction of stacking the magneto-resistance effect stack, wherein the upper shield electrode layer and the lower shield electrode layer supply sense current in the direction of stacking, and magnetically shield the magneto-resistance effect stack; a first bias magnetic layer which is provided on a surface of the magneto-resistance effect stack opposite to an air bearing surface, and wherein the first bias magnetic layer is magnetized in a direction perpendicular to said air bearing surface; and a pair of second bias magnetic layers provided on re

Abstract: A process for producing a magnetic recording medium is provided, the process comprising in sequence a step of forming a non-magnetic layer by applying a non-magnetic coating liquid above a non-magnetic support, a step of curing the non-magnetic layer by irradiation with radiation, and a step of forming a magnetic layer above the cured non-magnetic layer, the non-magnetic coating liquid comprising a resin having a hydroxy group and/or an amino group and a compound having an isocyanato group and/or a substituent represented by Formula (1) below and a radiation curing functional group. (In Formula (1) above, X1 is Formula (2) or Formula (3) below, and * denotes a bonding position).

Abstract: High magnetic moment films FeCo(X, Y), where X is a transition metal element and Y is a rare earth element are formed using off-axis static deposition techniques. The films have tunable magnetic anisotropy from 0 Oe to greater than 500 Oe that are thermally stable beyond nominal photoresist curing temperatures. By using off-axis static deposited FeCo(X, Y) films as seed layers to normally deposited FeCo films, inplane anisotropy and the magnetic moment can be controlled for specific design needs. Epitaxial-like growth (column-to-column matching) from the off-axis static FeCo(X,Y) seed layers to normally deposited FeCo films is attributed to sustained anisotropy in the entire film.

Abstract: In a method for manufacturing a magnetic recording medium, a plurality of vacuum film-formation devices formed separately and operated independently is prepared. The plurality of vacuum film-formation devices is connected by a connecting device provided with a disk transport system.

Abstract: A recording medium includes a substrate, a recording layer provided with perpendicular magnetic anisotropy for recording of information, a foundation layer disposed between the substrate and the recording layer, an initial layer which is greater in surface tension than the foundation layer and held in contact with a recoding-layer-side surface of the foundation layer, and a functional layer held in contact with a recoding-layer-side surface of the initial layer.

Abstract: The magnetic recording medium includes: a substrate; a recording layer formed in a predetermined concavo-convex pattern over the substrate, the concavo-convex pattern including a convex portion that serves as a recording element; and a filling portion that fills a concave portion between the recording elements. The filling portion comprises a metal-based main filling material and nitrogen. Nitrogen is unevenly distributed in the filling portion such that the ratio of the number of nitrogen atoms to the total number of atoms of the main filling material and nitrogen atoms is greater in the upper surface portion of the filling portion than in the lower portion thereof.

Abstract: Read elements and associated methods of fabrication are disclosed. During fabrication of the read element, and more particularly, the fabrication of the hard bias magnets, a non-magnetic sacrificial layer is deposited on top of the hard bias material. When a CMP process is subsequently performed, the sacrificial layer is polished instead of the hard bias material. The thicknesses of the hard bias magnets are not affected by the CMP process, but are rather defined by the deposition process of the hard bias material. As a result, the variations in the CMP process will not negatively affect the magnetic properties of the hard bias magnets so that they are able to provide substantially uniform effective magnetic fields to bias the free layer of the magnetoresistance (MR) sensor of the read element.

Abstract: A magnetic recording medium is provided in the present invention. The magnetic recording medium including a substrate; a base layer disposed on the substrate; an intermediate layer disposed on the base layer; and a recording layer disposed on the intermediate layer and including a magnetic matrix and a plurality of non-magnetic particles percolated in the magnetic matrix.

Abstract: A method of manufacturing a highly reliable magnetic head slider, with a simplified manufacturing process which provides reduction in manufacturing time and costs, is provided. The manufacturing method includes a multi-layer forming step for forming a magnetic head section in a multi-layered manner, the magnetic head section including a read element and/or a write element and a magnetic shield for magnetically shielding the read element and/or the write element, and the magnetic head slider is manufactured by being cut off from a multi-layered body having the magnetic head section. The manufacturing method further includes, after the multi-layer forming step, a shield end removing step for removing end portions in a width direction of the magnetic shield located on the flying surface side of the magnetic head slider.

Abstract: A method of manufacturing a magnetoresistance effect element having a high MR ratio even with a low RA and an apparatus of the same are provided. The magnetoresistance effect element having an MgO (magnesium oxide) layer provided between a ferromagnetic layer and a second ferromagnetic layer is manufactured by forming a film of the MgO layer in a film forming chamber in which a substance whose getter effect with respect to the oxidizing gas such as oxygen or water is large is adhered to the surfaces of components (an inner wall 37 of a film forming chamber in the interior of a first film forming chamber 21, inner walls of an adhesion preventing shield 36, a partitioning plate 22, a shutter or the like) provided in the chamber for forming the MgO layer. The substance having a large getter effect must simply be a substance whose value of oxygen gas adsorption energy is 145 kcal/mol or higher and, in particular, Ta (tantalum) as a substance which constitutes the magnetoresistance effect element is preferable.

Abstract: A thin film structure having a magnetic layer and a seed layer positioned adjacent to the magnetic layer is provided. The seed layer includes a L10 structure.

Abstract: In a magnetic recording medium which is able to cope with a higher recording density, there is provided a magnetic recording medium which has a higher retentivity and a lower noise, a production process thereof, and a magnetic recording and reproducing apparatus. The magnetic recording medium is characterized in that at least a non-magnetic base layer, a non-magnetic intermediate layer, a magnetic layer, and a protective layer are laminated in this order on a non-magnetic substrate, and at least one of the layers of the non-magnetic base layer is configured by a WX-based alloy or a MoX-based alloy (X?Zr, Nb, Hf, Ta).

Abstract: An information storage device comprises a ferroelectric media, write circuitry to provide a first signal and a second signal to the ferroelectric media, a tip platform and a cantilever operably associated with the tip platform. A tip extends from the cantilever toward the ferroelectric media and includes a first conductive material communicating the first signal from the write circuitry to the ferroelectric media and a second conductive material communicating the second signal from the write circuitry to the ferroelectric media. A insulating material arranged between the first conductive material and the second conductive material to electrically isolate the first conductive material from the second conductive material.

Abstract: Disclosed herein is a printing system is described having a first printer including a fuser employing fuser oil, and a coater disposed upstream or downstream from the first printer and being configured to deposit a wax coating on a portion of the substrate. A corresponding method and a substrate also are described. The system, method and substrate are useful for preparing MICR encoded documents such as checks.

Abstract: A magnetoresistive element (MR element) for reading a change in a magnetic field of a magnetic recording medium includes first and second electrode layers for providing a sensing current, which are perpendicular to an air bearing surface (ABS) facing the magnetic recording medium, first and second free layers which have a magnetization direction which changes in accordance with an external magnetic field, and a spacer layer composed of non-magnetic material. A ratio of a representative width and a representative length of each of the first and second free layers is at least 2 to 1, to thereby provide initial magnetizations along a direction of the representative length of each of the first and second free layers.