A multilayer exchange spring recording media consists of a magnetically hard magnetic storage layer strongly exchange coupled to a softer nucleation host. The strong exchange coupling can be through a coupling layer or direct. The hard magnetic storage layer has a strong perpendicular anisotropy. The nucleation host consists of one or more ferromagnetic coupled layers. For a multilayer nucleation host the anisotropy increases from layer to layer. The anisotropy in the softest layer of the nucleation host can be two times smaller than that of the hard magnetic storage layer. The lateral exchange between the grains is small. The nucleation host decreases the coercive field significantly while keeping the energy barrier of the hard layer almost unchanged. The coercive field of the total structure depends on one over number of layers in the nucleation host. The invention proposes a recording media that overcomes the writeability problem of perpendicular recording media.

A method includes generating synthetic data related to known defect patterns on surfaces of magnetic media using parameterized rules. A classifier model is trained with the synthetic data so that the classifier model learns how to detect and identify defect patterns on magnetic media. Performance of the classifier model is validated by using real defect pattern data. The classifier model is deployed for use in identifying defective data patterns on magnetic media test specimens. The classifier may be used before or after clustering defect data points on surfaces of magnetic media.

A multilayer exchange spring recording media consists of a magnetically hard magnetic storage layer strongly exchange coupled to a softer nucleation host. The strong exchange coupling can be through a coupling layer or direct. The hard magnetic storage layer has a strong perpendicular anisotropy. The nucleation host consists of one or more ferromagnetic coupled layers. For a multilayer nucleation host the anisotropy increases from layer to layer. The anisotropy in the softest layer of the nucleation host can be two times smaller than that of the hard magnetic storage layer. The lateral exchange between the grains is small. The nucleation host decreases the coercive field significantly while keeping the energy barrier of the hard layer almost unchanged. The coercive field of the total structure depends on one over number of layers in the nucleation host. The invention proposes a recording media that overcomes the writeability problem of perpendicular recording media.

A method of testing anti-high temperature performance of a magnetic head comprises applying a plurality of second magnetic fields with different intensities in a second direction to the magnetic head, and measuring a second output parameter curve, and judging whether a variation that is beyond an allowable value is presented on the second output parameter curve, therein the second direction passes through the ABS and at an angle whose absolute value is an acute angle to the ABS. The present invention can screen out defective magnetic heads that possess poor anti-high temperature performance without heating the magnetic head.

A tape head writer yoke pole tip and a substrate ground plane are electrically coupled to the resistance measuring module. An electrically conductive wear layer is disposed over the pole tip and a ground plane at the tape bearing surface, forming a closed circuit. A magnetic tape is transported across the tape head and wears away the wear layer. The resistance measuring module identifies when the circuit becomes open, and an amount of tape travel until the open circuit occurred, and transmits this to a host computer for determination of a tape abrasivity measure as a function of the amount of tape travel. The write element can be used for write operations while the wear layer is present, and after the wear layer has been worn away.

A probe configured to measure the magnetic permeability of a magnetic body includes a first signal conductor and a second signal conductor that form a pair of signal conductors, the first and second signal conductors being a signal transmission path, and tip ends of the first and second signal conductors being disposed away from a surface of the magnetic body by a predetermined gap length and at a predetermined interval from each other; a linear conductor that electrically connects the tip ends of the first and second signal conductors and that extends between the tip ends; and a first ground conductor and a second ground conductor that form a pair of ground conductors disposed in the vicinity of the pair of signal conductors, tip ends of the first and second ground conductor being in contact with the surface of the magnetic body.

A device for determining an external magnetic influence has a component comprising ferromagnetic material and a magnetizable region comprising at least three opposing magnetic tracks. The at least three magnetic opposing magnetic tracks are magnetizable in opposite directions, form at least two groups, and are arranged axially relative to the component. A first magnetic field sensor for emitting a signal is arranged radially to the component and assigned to the first group. A second magnetic field sensor for emitting a signal is arranged radially to the component and assigned to the second group. Redundant magnetic field sensors, each configured for emitting a signal, may be arranged radially in relation to the component for each of the first and second groups. The signals of the first and the second sensors can be set in relation to each other and in relation to the signals of the redundant first and second sensors.

According to one embodiment, a tester includes a magnetic shield portion having a space which is shielded from an external magnetic field, a controller generating a test signal for testing a magnetic memory having a magnetoresistive element provided in the space, an interface portion in the space, the interface portion which functions as an interface between the controller and the magnetic memory, and a magnetic field generating portion in the space, the magnetic field generating portion generating a test magnetic field while the magnetic memory is tested by the test signal.

A method and apparatus for testing a magnetic memory device is provided. The method begins when a magnetic field enhancing backing plate is installed in the test fixture. The magnetic field enhancing backing plate may be installed in the wafer chuck of a wafer testing probe station. The magnetic memory device is installed in the test fixture and a magnetic field is applied to the magnetic memory device. The magnetic field may be applied in-plane or perpendicular to the magnetic memory device. The performance of the magnetic memory device may be determined based on the magnetic field applied to the device. The apparatus includes a magnetic field enhancing backing plate adapted to fit a test fixture, possibly in the wafer chuck. The magnetic field enhancing backing plate is fabricated of high permeability magnetic materials, such as low carbon steel, with a thickness based on the magnetic field used in testing.

A method and device for determining values of a magnetic field component of a magnetic vector field.

A method for determining values of a magnetic field component of a magnetic vector field, comprising: determining first distribution data comprising values of the magnetic field component, for a first predetermined area defined along a predetermined surface; determining second distribution data comprising second values of the component of the magnetic field for a second predetermined area defined along a second predetermined surface, wherein the first and the second predetermined surfaces are parallel;
wherein determining second distribution data comprises manipulation of the first distribution data based on making use of intrinsic physical properties of the magnetic field; and associated device.