Abstract: Provided are a magnetic recording medium suitable for use with a microwave assisted magnetic recording head and suitable for such recording and a method for manufacturing the same. A perpendicular magnetic recording medium includes a recording layer including a plurality of magnetic layers. A magnetic layer as an uppermost layer of the recording layer includes three or more of sub-layers each having thickness of more than 0 and 1 nm or less, the sub-layers including a first sub-layer and a second sub-layer to make up a lamination unit layer, the first sub-layer including, as a major element, 50% or more of at least one type of element selected from the group consisting of Co, Fe and Ni, the second sub-layer including, as a major element, an element different from the major element of the first sub-layer.

Abstract: In a Spin Torque Oscillator (STO) comprising an underlayer, a first magnetic layer disposed on the underlayer, a non-magnetic intermediate layer disposed on the first magnetic layer, and a second magnetic layer disposed on the non-magnetic intermediate layer, the non-magnetic intermediate layer is a non-magnetic alloy containing 50 at % or more of at least one kind of element selected from a first group consisting of Cu, Ag, and Au, and further at least 0.1 at % or more in total of at least one kind of element selected from a second group consisting of Cu, Ag, Au, Cr, Ti, Zr, Hf, V, Nb, Ta, Ru, Os, Pd, Pt, Rh, and Ir that does not overlap with the element from the first group.

Abstract: To uniformly determine the positional relationship between a main magnetic pole and a spin torque oscillator while independently optimizing the main magnetic pole and the spin torque oscillator. On a trailing end surface of a main magnetic pole, a step is provided at the boundary between the main magnetic pole and a gap material disposed on both sides thereof, and a spin torque oscillator is formed on the step. The spin torque oscillator is effectively separated into two regions by utilizing the step. Further, a part of the spin torque oscillator is removed so as to disable the unwanted region, thereby realizing a self-alignment type high frequency magnetic field assisted magnetic recording head structure such that the positions of the end portions of the main magnetic pole and the spin torque oscillator are aligned.

Abstract: To provide a spin torque oscillator which is adapted to high data transfer rates and which can perform assisted magnetic recording of sufficient magnitude. A spin torque oscillator is provided with a stacked spin injection layer and a high frequency magnetic field generation layer. The stacked spin injection layer has a stacked structure in which a first magnetic layer, a coupling layer, and a second magnetic layer are stacked in the order mentioned from a far side as viewed from the high frequency magnetic field generation layer. Magnetization of the first magnetic layer and magnetization of the second magnetic layer are coupled antiparallel to each other. A polarity of the magnetization of the second magnetic layer is reversed temporally earlier than a magnetic field polarity reversal of a leakage magnetic field from the main magnetic pole.

Abstract: According to one embodiment, a differential magnetoresistive effect element comprises a first magnetoresistive effect element having a first pinning layer, a first intermediate layer, and a first free layer. The differential magnetoresistive effect element also comprises a second magnetoresistive effect element stacked via a spacer layer above the first magnetoresistive effect element, the second magnetoresistive effect element having a second pinning layer, a second intermediate layer, and a second free layer. The first magnetoresistive effect element and the second magnetoresistive effect element show in-opposite-phase resistance change in response to a magnetic field in the same direction, and tp2>tp1 is satisfied when a thickness of the first pinning layer is tp1, and a thickness of the second pinning layer is tp2. In another embodiment, the first and second magnetoresistive effect elements may be CPP-GMR elements.

Abstract: A spin torque oscillator generates a strong high-frequency magnetic field stably and has high reliability. A magnetic recording head includes a main magnetic pole and a spin torque oscillator. A magnetization control layer is antiferromagnetically coupled via a non-magnetic coupling layer with an interface contacting a high-frequency magnetic field generation layer of the spin torque oscillator.

Abstract: In high frequency magnetic assisted recording technique, a spin torque oscillator that stably oscillates at a low current and a magnetic recording head with high recording density are provided. In a magnetic recording head including an oscillator that generates a high frequency magnetic field, a spin injection layer structure of two laminated magnetic layers which are coupled to be anti-parallel is adopted. A product Ms×t of the saturated magnetization Ms and the film thickness t of the first magnetic layer close to a field generation layer is smaller than a product Ms×t of the second magnetic layer remote from the field generation layer.

Abstract: The strength of a magnetic field applied from a main pole to an oscillator and the strength of a magnetic field applied from the main pole to a recording medium are improved in a magnetic recording head for microwave assisted recording. In the magnetic recording head according to the present invention, an interval between the main pole and a trailing shield at a place in a position above an air bearing surface is larger than an interval between the main pole and the trailing shield on the air bearing surface.

Abstract: In high frequency magnetic assisted recording technique, a spin torque oscillator that stably oscillates at a low current and a magnetic recording head with high recording density are provided. In a magnetic recording head including an oscillator that generates a high frequency magnetic field, a spin injection layer structure of two laminated magnetic layers which are coupled to be anti-parallel is adopted. A product Ms×t of the saturated magnetization Ms and the film thickness t of the first magnetic layer close to a field generation layer is smaller than a product Ms×t of the second magnetic layer remote from the field generation layer.

Abstract: The present invention provides a spin torque oscillator that can realize stable oscillation and has high reliability. A laminated structure including a first magnetic layer 1 having a bcc crystal structure and having in-plane magnetic anisotropy and a second magnetic layer 2 having perpendicular magnetic anisotropy laminated on the first magnetic layer 1 and including a multilayer film of Co and Ni is used.

Abstract: A magnetoresistive magnetic head according to one embodiment uses a current-perpendicular-to-plane magnetoresistive element having a laminate of a free layer, an intermediate layer, and a pinned layer, the pinned layer being substantially fixed to a magnetic field to be detected, wherein either the pinned layer or the free layer includes a Heusler alloy layer represented by a composition of X—Y—Z, wherein X is between about 45 at. % and about 55 at. % and is Co or Fe, Y accounts for between about 20 at. % and about 30 at. % and is one or more elements selected from V, Cr, Mn, and Fe, and Z is between about 20 at. % and about 35 at.

Abstract: The present invention provides a magnetic recording head and a magnetic recording device that realize information transfer speed exceeding 1 Gbit/s in microwave assisted magnetic recording applied to a magnetic recording device having recording density exceeding 1 Tbit/in2. Concerning a reference layer that supplies spin torque to a high-speed magnetization rotator serving as a microwave field generation source, when an externally applied field to the reference layer is represented as Hext, a magnetic anisotropy field of the reference layer is represented as Hk, and an effective demagnetizing field in a vertical direction of a film surface of the reference layer is represented as Hd-eff, the fixing layer is configured to satisfy conditions Hext?Hk+Hd-eff>0 and Hext+Hk?Hd-eff>0.

Abstract: The present invention provides a spin torque oscillator that can realize stable oscillation and has high reliability. A laminated structure including a first magnetic layer 1 having a bcc crystal structure and having in-plane magnetic anisotropy and a second magnetic layer 2 having perpendicular magnetic anisotropy laminated on the first magnetic layer 1 and including a multilayer film of Co and Ni is used.

Abstract: Embodiments of the present invention provide a magnetic head incorporating a CPP-GMR device having a high output at a suitable resistance. According to one embodiment, in a Current Perpendicular to Plane-Giant Magneto Resistive (CPP-GMR) head comprising a pinned layer, a free layer, and a current screen layer for confining current therein, a planarization treatment is applied to the surface of the current screen layer, thereby allowing the current screen layer to have a fluctuation in film thickness thereof. As a result of the fluctuation being provided in the film thickness of the current screen layer, parts of the current screen layer, smaller in the film thickness, will be selectively turned into metal areas low in resistance, and as the metal areas low in resistance serve as current paths, effects of confining current can be adjusted by controlling the fluctuation in the film thickness.

Abstract: One general embodiment of the present invention is a magnetic read head including a magnetoresistive sensor where sense current flows in a stacking direction of the magnetoresistive sensor, i.e., perpendicular to the plane of the layers of the head. The magnetoresistive sensor comprises a free layer having a magnetization direction that is affected by external magnetic fields and includes a Heusler alloy layer and a Co-based amorphous metal layer, a fixed layer which is stacked with the free layer and has a fixed magnetization direction, and a non-magnetic intermediate layer between the free layer and the fixed layer.

Abstract: Provided is a differential type reproduction head which can obtain a preferable bit error rate without causing a baseline shift even when two magnetoresistive elements have different maximum resistance change amounts. The differential type reproduction head has a layered structure formed by a first magnetoresistive element having a first free layer, a differential gap layer, and a second magnetoresistive element having a second free layer. When DR1 and DR2 are the maximum resistance change amounts of the first magnetoresistive element and the second magnetoresistive element, respectively, HB1 is a magnetic domain control field applied to the first free layer, and HB2 is a magnetic domain control field applied to the second free layer, the following relationships are satisfied: HB1>HB2 when DR1>DR2; HB2>HB1 when DR2>DR1.

Abstract: Embodiments of the present invention provides sufficiently high exchange coupling with a magnetic layer and improve the yield and reliability of a magnetoresistive head. By using a tilted growth crystalline structured antiferromagnetic film manufactured by an oblique incident deposition method, a high exchange coupling field with a ferromagnetic film can be obtained. As a result, excellent reliability and high output can be obtained in a magnetoresistive head utilizing features in accordance with embodiments of the present invention.

Abstract: A magnetoresistive magnetic head according to one embodiment uses a current-perpendicular-to-plane magnetoresistive element having a laminate of a free layer, an intermediate layer, and a pinned layer, the pinned layer being substantially fixed to a magnetic field to be detected, wherein either the pinned layer or the free layer includes a Heusler alloy layer represented by a composition of X-Y-Z, wherein X is between about 45 at. % and about 55 at. % and is Co or Fe, Y accounts for between about 20 at. % and about 30 at. % and is one or more elements selected from V, Cr, Mn, and Fe, and Z is between about 20 at. % and about 35 at.

Abstract: One general embodiment of the present invention is a magnetic read head including a magnetoresistive sensor where sense current flows in a stacking direction of the magnetoresistive sensor, i.e., perpendicular to the plane of the layers of the head. The magnetoresistive sensor comprises a free layer having a magnetization direction that is affected by external magnetic fields and includes a Heusler alloy layer and a Co-based amorphous metal layer, a fixed layer which is stacked with the free layer and has a fixed magnetization direction, and a non-magnetic intermediate layer between the free layer and the fixed layer.

Abstract: According to one embodiment, a differential magnetoresistive effect element comprises a first magnetoresistive effect element having a first pinning layer, a first intermediate layer, and a first free layer. The differential magnetoresistive effect element also comprises a second magnetoresistive effect element stacked via a spacer layer above the first magnetoresistive effect element, the second magnetoresistive effect element having a second pinning layer, a second intermediate layer, and a second free layer. The first magnetoresistive effect element and the second magnetoresistive effect element show in-opposite-phase resistance change in response to a magnetic field in the same direction, and tp2>tp1 is satisfied when a thickness of the first pinning layer is tp1, and a thickness of the second pinning layer is tp2. In another embodiment, the first and second magnetoresistive effect elements may be CPP-GMR elements.