65results about "Materials with non-metallic substances" patented technology

Provided is a magnetic tape device in which a magnetic tape transportation speed is equal to or lower than 18 m / sec, Ra measured regarding a surface of a magnetic layer of a magnetic tape is equal to or smaller than 2.0 nm, a C-H derived C concentration calculated from a C-H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %, and ΔSFD (=SFD25° C.−SFD−190° C.) in a longitudinal direction of the magnetic tape is equal to or smaller than 0.50, with the SFD25° C. being SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25° C., and the SFD−190° C. being SFD measured at a temperature of −190° C.

Provided is a magnetic tape device in which a magnetic tape transportation speed is equal to or lower than 18 m / sec, Ra measured regarding a surface of a magnetic layer of a magnetic tape is equal to or smaller than 2.0 nm, a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %, and ΔSFD (=SFD25°C.−SFD−190° C.) in a longitudinal direction of the magnetic tape is equal to or smaller than 0.50, with the SFD25° C. being SFD measured in a longitudinal direction of the magnetic tape at a temperature of 25° C., and the SFD−190° C. being SFD measured at a temperature of −190° C.

The magnetic tape has a nonmagnetic layer containing nonmagnetic powder and binder on a nonmagnetic support, and a magnetic layer containing ferromagnetic powder and binder on the nonmagnetic layer; wherein the combined thickness of the nonmagnetic layer and the magnetic layer is less than or equal to 0.60 μm, the coefficient of friction as measured on the base portion of the surface of the magnetic layer is less than or equal to 0.35, at least the magnetic layer contains one or more components selected from the group consisting of a fatty acid and a fatty acid amide, and a C—H derived carbon, C, concentration calculated from a C—H peak area ratio in a C1s spectrum obtained by X-ray photoelectron spectroscopy conducted at a photoelectron take-off angle of 10 degrees on the surface of the magnetic layer is greater than or equal to 45 atom %.

Provided is an iron nitride-based magnetic powder that comprises magnetic particles having a mean particle size of at most 20 nm. The magnetic particle has a core of a main phase of Fe 16 N 2 and has, on the outer side of the core, an oxide phase derived from a metal Fe phase formed by reduction of iron nitride. In relation to the weatherability index s and the saturation magnetization s thereof, the magnetic powder satisfies s 0.8 x s - 30. In this, s = (s - s 1 ) / s x 100. s 1 means the saturation magnetization of the magnetic powder kept in an atmosphere of 60 DEG C and 90 % RH for 1 week. The powder can be obtained by exposing powder particles having a main phase of Fe 16 N 2 to a reducing gas to partly reduce the region of the surface of the particles into a metal Fe phase (gradual reduction) followed by exposing them to an oxidizing gas to oxidize a part of the surface of the metal Fe phase into an oxide phase (gradual oxidation).

A magnetic powder is provided composed of particles that, even when the particle size is refined, exhibits excellent magnetic properties, in particular, a high coercive force, for use in a high-density recording medium. The invention also provides a magnetic recording medium using the powder. The powder is an iron system magnetic powder containing, as an atomic ratio of Fe, a total of 0.01 to 10 atom% of one or more selected from W and Mo, particularly a magnetic powder comprised mainly of Fe16N2. The magnetic powder is able to exhibit a high coercive force of 238 kA / m (3000 Oe) or more. In addition to the W and Mo, the magnetic powder may contain, as an atomic ratio of Fe, a total of up to 25 atom% of one or more selected from Al and a rare earth element (defined as including Y).