An alloy is provided which consists of Fe.sub.100-a-b-c-d-x-y-zCu.sub.aNb.sub.bM.sub.cT.sub.dSi.sub.xB.sub.yZ.sub.z and up to 1 at % impurities, M being one or more of the elements Mo, Ta and Zr, T being one or more of the elements V, Mn, Cr, Co and Ni, Z being one or more of the elements C, P and Ge, 0 at %≦a<1.5 at %, 0 at %≦b<2 at %, 0 at %≦(b+c)<2 at %, 0 at %≦d<5 at %, 10 at %<x<18 at %, 5 at %<y<11 at % and 0 at %≦z<2 at %. The alloy is configured in tape form and has a nanocrystalline structure in which at least 50 vol % of the grains have an average size of less than 100 nm, a hysteresis loop with a central linear region, a remanence ratio Jr/Js of <0.1 and a coercive field strength H.sub.c to anisotropic field strength H.sub.a ratio of <10%.

An amorphous lamination core for motor is configured by laminating amorphous alloy pieces, a pressurization member is pressed to a plurality of positions of the amorphous alloy piece, the number of pressurization portions with a crack is N, the total number of pressurization portions to which the pressurization member is pressed is N0 (N0≥100), and a degree of embrittlement is N/N0×100(%), the pressurization member is made of beryllium copper, and has a body portion of φ1.4 mm and a conical portion, the conical portion has a bottom surface of φ4 mm and a vertex angle θ of 120°, and when the degree of embrittlement is evaluated with the conical portion being pressed against the amorphous alloy piece and pressurization force of the pressurization member being set to 14 N, a degree of embrittlement of the amorphous alloy piece is equal to or less than 3.0%.

A soft magnetic alloy is represented by a composition formula (Fe.sub.1-xA.sub.x).sub.aSi.sub.bB.sub.cCu.sub.dM.sub.e, wherein A is at least one of Ni and Co, M is one or more selected from the group consisting of Nb, Mo, V, Zr, Hf, and W, and 82.4≤a≤86, 0.2≤b≤2.4, 12.5≤c≤15.0, 0.05≤d≤0.8, 0.4≤e≤1.0, and 0≤x≤0.1 in at %, and has a structure in which crystal grains having a grain size of 60 nm or less are present in an amorphous phase.

A high-frequency acceleration cavity core is a toroidal core obtained by winding an Fe-based magnetic ribbon having crystals with an average crystal grain size of 1 μm or less, in which a space factor of the Fe-based magnetic ribbon is 40% or more and 59% or less, and a μQf value at 1 MHz is 3×10.sup.9 Hz or more. The average crystal grain size is preferably 0.1 μm or less. The toroidal core preferably has a portion having a gap portion from an inner diameter to an outer diameter.

An inductor includes a first magnetic body having a toroidal shape and having a ferrite; and a second magnetic body configured to be different from the first magnetic body and including a metal ribbon, wherein the second magnetic body includes an outer magnetic body disposed on an outer circumferential surface of the first magnetic body and an inner magnetic body disposed on an inner circumferential surface of the first magnetic body, and each of the outer magnetic body and inner magnetic body is wound in a plurality of layers in a circumferential direction of the first magnetic body.

A magnetic ribbon according to an embodiment has a crystallinity degree of 0.05 or higher and 0.4 or lower when the magnetic ribbon is subjected to XRD analysis, the magnetic ribbon being Fe—Nb—Cu—Si—B-base, and the crystallinity degree being expressed by “a peak total area of a crystalline phase”/(“a peak area of an amorphous phase”+“the peak total area of the crystalline phase”). Also, the magnetic ribbon is preferred to have a region in which a KIKUCHI pattern is detected when the crystalline phase is subjected to EBSD analysis. Also, the thickness of the magnetic ribbon is preferred to be 25 μm or less.

A method of producing a laminated amorphous alloy ribbon holding spool. The method includes providing amorphous alloy ribbon holding spools, each of which is wound with a single layer amorphous alloy ribbon, unwinding the single layer amorphous alloy ribbon from each of the amorphous alloy ribbon holding spools, making the single layer amorphous alloy ribbon travel with a laser being radiated thereto, to thereby simultaneously prepare single layer amorphous alloy ribbons having laser irradiation mark formed thereon, laminating the single layer amorphous alloy ribbons having the laser irradiation mark formed thereon to, thereby prepare a laminated amorphous alloy ribbon, and winding up the laminated amorphous alloy ribbon on a spool.

The invention discloses a method and its device for preparing a magnetic core with amorphous ribbon. The magnetic core is prepared with amorphous ribbon, the size of the amorphous ribbon is controlled according to the target requirements, and the magnetic core with required size and shape is prepared according to the target requirements; the single-roller rapid quenching technology with online automatic segmentation and automatic storage capability is used for preparation, which can control the length, width and thickness of the amorphous ribbon according to the target requirements; the amorphous ribbon segmented by single-roller rapid quenching technology is used to spray and cool down one by one, and then air-dry, transfer, spray adhesive and online store it one by one; the stored amorphous ribbon is reshaped, compressed and heat-treated successively, and then demoulded to prepare a magnetic core.

A punching method with a favorable punchability with respect to amorphous metal thin ribbons, an amorphous metal thin strip produced by the method, and a laminated core, are provided. The amorphous metal thin strip has a thickness of from more than 30 μm to 50 μm, and a side configured by a punched surface on which at least a shear droop, a shearing surface, and a fractured surface are observed, the width of the shear droop relative to the thickness of the metal thin strip being 30% or less at the side.

A method of producing a laminated amorphous alloy ribbon holding spool. The method includes providing amorphous alloy ribbon holding spools, each of which is wound with a single layer amorphous alloy ribbon, unwinding the single layer amorphous alloy ribbon from each of the amorphous alloy ribbon holding spools, making the single layer amorphous alloy ribbon travel with a laser being radiated thereto, to thereby simultaneously prepare single layer amorphous alloy ribbons having laser irradiation mark formed thereon, laminating the single layer amorphous alloy ribbons having the laser irradiation mark formed thereon to, thereby prepare a laminated amorphous alloy ribbon, and winding up the laminated amorphous alloy ribbon on a spool.