Provided are: a magnetic recording medium including a non-magnetic support and a magnetic layer containing a ferromagnetic powder, in which the ferromagnetic powder is an ε-iron oxide powder, a vertical magnetization amount Φm per unit area of the magnetic recording medium is 5 G.Math.μm or more and 100 G.Math.μm or less at a measurement temperature of 25° C., and an inclination of Φm obtained from Φm at a measurement temperature of 10° C., Φm at a measurement temperature of 25° C., and Φm at a measurement temperature of 40° C. is −0.20 G.Math.μm/° C. or more and −0.03 G.Math.μm/° C. or less; a magnetic tape cartridge including the magnetic recording medium which is a magnetic tape; and a magnetic recording and reproducing device including the magnetic recording medium.

Provided are: a magnetic recording medium including a non-magnetic support and a magnetic layer containing a ferromagnetic powder, in which the ferromagnetic powder is an ε-iron oxide powder, a vertical squareness ratio SQ of the magnetic recording medium is 0.50 or more and 0.95 or less at a measurement temperature of 25° C., and an inclination of SQ obtained from SQ at a measurement temperature of 10° C., SQ at a measurement temperature of 25° C., and SQ at a measurement temperature of 40° C. is −0.0050° C..sup.−1 or more and −0.0003° C..sup.−1 or less; a magnetic tape cartridge including the magnetic recording medium which is a magnetic tape; and a magnetic recording and reproducing device including the magnetic recording medium.

[Object] To provide technologies such as an orientation device capable of increasing strength of a magnetic field in a transport path. [Solving Means] An orientation device according to the present technology includes a transport path, a permanent magnet portion, and a yoke portion. The transport path allows a base on which a magnetic coating film containing magnetic powder has been formed to pass through the transport path along a transport direction. The permanent magnet portion includes a plurality of first permanent magnets, and a plurality of second permanent magnets that is opposed to the plurality of first permanent magnets across the transport path in a vertical direction that is vertical to the transport direction in a manner that opposite poles face each other, the permanent magnet portion vertically orienting particles of the magnetic powder by applying a magnetic field to the magnetic coating film on the base that passes through the transport path. The yoke portion is made of a soft magnetic material, and connects to poles on a side opposite to the transport path side of the plurality of first permanent magnets, and to poles on a side opposite to the transport path side of the plurality of second permanent magnets.

[Object] To provide technologies such as an orientation device capable of increasing strength of a magnetic field in a transport path. [Solving Means] An orientation device according to the present technology includes a transport path, a permanent magnet portion, and a yoke portion. The transport path allows a base on which a magnetic coating film containing magnetic powder has been formed to pass through the transport path along a transport direction. The permanent magnet portion includes a plurality of first permanent magnets, and a plurality of second permanent magnets that is opposed to the plurality of first permanent magnets across the transport path in a vertical direction that is vertical to the transport direction in a manner that opposite poles face each other, the permanent magnet portion vertically orienting particles of the magnetic powder by applying a magnetic field to the magnetic coating film on the base that passes through the transport path. The yoke portion is made of a soft magnetic material, and connects to poles on a side opposite to the transport path side of the plurality of first permanent magnets, and to poles on a side opposite to the transport path side of the plurality of second permanent magnets.

Provided is a powder of a β-iron oxyhydroxide-based compound that is a group of particles of a β-iron oxyhydroxide-based compound represented by Formula (1) below; in which a surface of the particles of the β-iron oxyhydroxide-based compound is modified with a surface modifier; in which, in a case where the powder is dispersed in water to be made into a sol, a zeta potential of the powder is equal to or higher than +5 mV at pH 10; and
β-A.sub.aFe.sub.1-aOOH  (1)
in which, in Formula (1), A represents at least one metallic element other than Fe, and a represents a number that satisfies a relationship of 0≤a<1.

Provided is a powder of a β-iron oxyhydroxide-based compound that is a group of particles of a β-iron oxyhydroxide-based compound represented by Formula (1) below; in which a surface of the particles of the β-iron oxyhydroxide-based compound is modified with a surface modifier; in which, in a case where the powder is dispersed in water to be made into a sol, a zeta potential of the powder is equal to or higher than +5 mV at pH 10; and
β-A.sub.aFe.sub.1-aOOH  (1)
in which, in Formula (1), A represents at least one metallic element other than Fe, and a represents a number that satisfies a relationship of 0≤a<1.

There is provided an oriented body containing platinum group-substituted-6 iron oxide particles typified by Rh-substituted ε-iron oxide or Ru-substituted ε-iron oxide applicable to MAMR, MIMR, or F-MIMR system, and a technique related thereto, containing platinum group element-substituted ε-iron oxide particles in which a part of ε-iron oxide is substituted with at least one element of platinum group elements, as magnetic particles wherein the degree of orientation of the magnetic particles defined by the degree of orientation=SQ (direction of magnetization easy-axes)/SQ (direction of magnetization hard-axes) exceeds 5.0, and a coercive force exceeds 31 kOe.

[Object] To provide technologies such as an orientation device capable of increasing strength of a magnetic field in a transport path.

[Solving Means] An orientation device according to the present technology includes a transport path, a permanent magnet portion, and a yoke portion. The transport path allows a base on which a magnetic coating film containing magnetic powder has been formed to pass through the transport path along a transport direction. The permanent magnet portion includes a plurality of first permanent magnets, and a plurality of second permanent magnets that is opposed to the plurality of first permanent magnets across the transport path in a vertical direction that is vertical to the transport direction in a manner that opposite poles face each other, the permanent magnet portion vertically orienting particles of the magnetic powder by applying a magnetic field to the magnetic coating film on the base that passes through the transport path. The yoke portion is made of a soft magnetic material, and connects to poles on a side opposite to the transport path side of the plurality of first permanent magnets, and to poles on a side opposite to the transport path side of the plurality of second permanent magnets.

A method of encoding information in an object that may allow for enhanced tailorability of the encoding during the processing and/or also enhance the amount of information encoded in the object. More particularly, the method of encoding the object enables the magnetic characteristics at different spatial locations of the object to be modified to form a spatial array of the different magnetic characteristics for representing the encoded information. The method can be used to permanently embed a magnetic signature in a non-magnetic object, for example. More specifically, the method allows different portions of the object to exhibit different magnetic characteristics at each spatial location of the object in three dimensions, and more particularly configuring the magnetic vectors of those portions in many possible orientations with a 4n steradian solid angle and/or with different intensities.

A method of encoding information in an object that may allow for enhanced tailorability of the encoding during the processing and/or also enhance the amount of information encoded in the object. More particularly, the method of encoding the object enables the magnetic characteristics at different spatial locations of the object to be modified to form a spatial array of the different magnetic characteristics for representing the encoded information. The method can be used to permanently embed a magnetic signature in a non-magnetic object, for example. More specifically, the method allows different portions of the object to exhibit different magnetic characteristics at each spatial location of the object in three dimensions, and more particularly configuring the magnetic vectors of those portions in many possible orientations with a 4n steradian solid angle and/or with different intensities.