Hitachi Metals, Ltd.

Other

Applied Magnetics, LLC

Masahiro Tobise

Hiroshi Okajima

Mikio Shindo

Keitaro Yamashita

Katsunori Iwasaki

Yasunobu Ogata

Chiharu Mitsumata

Simon H Liao

Kazuhiro Yamamura

Tetsurou Kawai

Hisayuki Miura

Disclosed is a hydrogen separation alloy which is adoptable to a product having a large surface area of a side where hydrogen permeates and which has such a metallographic structure as to improve hydrogen permeability and to improve hydrogen-embrittlement resistance. The hydrogen separation alloy used herein is represented by the compositional formula: NbMMwhere Mis at least one element selected from the group consisting of Ti, Zr and Hf; Mis at least one element selected from the group consisting of Ni, Co, Cr, Fe, Cu and Zn; 10&#x2266;&#x3b1;&#x2266;60, 10&#x2266;&#x3b2;&#x2266;50, and &#x3b1;+&#x3b2;&#x2266;80. The alloy contains inevitable impurities. And the alloy includes two phases, i.e., an Nb-Mphase serving as a hydrogen-permeable phase, and a M-Mphase serving as a hydrogen-embrittlement-resistant phase. The hydrogen-permeable phase and the hydrogen-embrittlement-resistant phase have an elongated structure resulting from rolling. The hydrogen-permeable phase occupies 35% to 70% of an arbitrary 10 &#x3bc;m&#xd7;10 &#x3bc;m region in a 50 &#x3bc;m&#xd7;50 &#x3bc;m observation plane of a cross section of the alloy under an electron microscopic observation, the cross section is taken in a direction of thickness reduced by the rolling and in a direction of rolling and flattening.

Hydrogen separation alloy and method for producing same

A resin-bonded magnet composed substantially of (a) an R&mdash;T&mdash;N-based magnetic powder having a basic composition of R T N , wherein R is at least one selected form the group consisting of rare earth elements including Y, T is Fe or Fe and Co, 5&lE;&agr;&lE;20, and 5&lE;&bgr;&lE;30, (b) a ferrite magnetic powder having a substantially magnetoplumbite-type crystal structure and a basic composition represented by (A R&prime; ) O&lsqb;(Fe M ) O &rsqb; by atomic ratio, wherein A is Sr and/or Ba, R&prime; is at least one selected from the group consisting of rare earth elements including Y, La being indispensable, M is Co or Co and Zn, 0.01&lE;x<0.4, 0.005&lE;y&lE;0.04, and 5.0&lE;n&lE;6.4, and (c) a binder. The ferrite magnet powder is preferably an anisotropic, granulated powder or an anisotropic, sintered ferrite magnet powder.

Resin-bonded magnet, its product, and ferrite magnet powder and compound used therefor

A magnet roll has a plurality of magnetic poles on a surface with at least one magnetic pole portion being composed of an anisotropic bonded magnet including magnet powder and binder resin. The anisotropic bonded magnet contains R&mdash;T&mdash;N magnet powder, wherein R is at least one rare earth element including Y, Sm being indispensable, and T is Fe or Fe and Co. The R&mdash;T&mdash;N magnet powder may also contain inevitable impurities such as C, O and H. The binder resin constitutes 20-70% of the volume of the anisotropic bonded magnet such that the anisotropic bonded magnet have a maximum energy product (BH) of 10 MGOe or more and a residual magnetization Br of 2800 G or more.

Magnet roll having an anisotropic bonded magnet portion containing rare earth-iron-nitrogen magnet powder

A nitride-type, rare earth magnet material having a basic composition represented by R T M B N (atomic %), wherein R is at least one rare earth element including Y, as a rare earth element Sm must be present, T is Fe alone or a combination of Fe and Co and/or Ni, M is at least one element selected from the group consisting of Al, Ti, V, Cr, Mn, Cu, Ga, Zr, Nb, Mo, Hf, Ta, W and Zn, 6&lE;&agr;&lE;15, 0.5&lE;&bgr;&lE;10, 0&lE;&ggr;&lE;4, and 4&lE;&dgr;&lE;30, which is substantially composed of a hard magnetic phase of an R T -type structure having an average crystal grain size of 0.01-1 &mgr;m, an average area ratio of &agr;-Fe being 5% or less.

Nitride type, rare earth magnet materials and bonded magnets formed therefrom

An SAL-type magnetoresistive playback head that is highly sensitive and that limits Barkhausen noise is provided by optimizing the magnetic properties of the permanent magnet film. On top of a lower insulating layer are stacked a soft magnetic bias film (SAL film), a magnetic separating film (shunt film), a magnetoresistive film (MR film), and an upper insulating layer, in that order. The outer sides of the track of the MR film are in direct contact with the permanent magnet film or in indirect contact via a base film. Alternatively, the present invention relates to a spin-valve magnetoresistive playback head. On top of a lower insulating layer are stacked an anti-ferromagnetic film, a fixed magnetizing film, a magnetic separating film, a movable magnetizing film (MR film), and an upper insulating layer, in that order. The outer sides of the track of the movable magnetizing film are in direct contact with the permanent magnet film or in indirect contact via a base film. In either type of playback head, Barkhausen noise is eliminated by using a CoCrPt alloy film having a composition that provides the magnetic properties needed for a permanent magnet film that can handle narrow tracks and narrow gaps, and by specifying a ratio between the thicknesses of the MR film and the permanent magnet film.

Growing community of inventors

Saitama-ken, Japan

Masahiro Tobise