A grain-oriented electrical steel sheet for a wound transformer core. The steel sheet having a sheet thickness t, where t and an iron loss deterioration ratio obtained by subjecting the steel sheet under elliptic magnetization satisfy the following relations: (i) when t0.20 mm, the iron loss deterioration ratio is 60% or less; (ii) when 0.20 mm<t<0.27 mm, the iron loss deterioration ratio is 55% or less; and (iii) when 0.27 mmt, the iron loss deterioration ratio is 50% or less. The iron loss deterioration ratio is calculated from ((W.sub.AW.sub.B)/W.sub.B)100, where W.sub.A is iron loss under 50 Hz elliptic magnetization of 1.7 T in a rolling direction and 0.6 T in a direction orthogonal to the rolling direction, and W.sub.B is iron loss under 50 Hz alternating magnetization of 1.7 T in the rolling direction.

A magnetic body of the coil component is constituted by soft magnetic metal grains joined together via a glass phase, wherein the soft magnetic metal grains contain Fe in their metal part and also have, on their surface, an amorphous insulation layer containing Si and O, and wherein the percentage by mass of Si relative to all elements in the insulation layer is higher than that in the glass phase. The coil component can offer improved dielectric breakdown voltage.

Disclosed is a magnetic field shielding unit for magnetic security transmission. The magnetic field shielding unit for magnetic security transmission includes a magnetic shielding layer formed of fragments of ferrite containing magnesium oxide (MgO) shredded to improve flexibility of the magnetic field shielding unit. The ferrite containing magnesium oxide has a real part () of the complex permeability of 650 or more at a frequency of 100 kHz. Accordingly, it is possible to prevent influence of a magnetic field on components of a mobile terminal device or a body of a user who uses the same, and to further increase the characteristics of the combined antennas even if the magnetic field shielding unit is combined with various kinds and purposes of antennas having various structures, shapes, sizes and intrinsic characteristics (inductance, resistivity, etc.).

An electronic component includes a composite body composed of a composite material of a resin and a magnetic metal powder and a metal film disposed on an outer surface of the composite body. The magnetic metal powder contains Fe. The metal film mainly contains Ni and is in contact with the resin and the magnetic metal powder.

A magnetic core excellent in productivity, having stable magnetic characteristics, and easy to handle for a coil device including a conductor and is formed by stacking a plurality of soft magnetic thin ribbons divided into small pieces.

A magnetic powder includes a core portion containing a soft magnetic material, a foundation layer that is provided at a surface of the core portion, that contains an oxide of the soft magnetic material, and that has an average thickness of 0.1 nm or more and less than 10 nm, and an insulating layer that is provided at a surface of the foundation layer, and that contains an organosiloxane compound as a main material, wherein the organosiloxane compound has a C/Si atomic ratio of 0.01 or more and 2.00 or less.

Vibration of an iron core is reduced to reduce transformer noise. An iron core for a transformer comprises a plurality of grain-oriented electrical steel sheets stacked together, wherein at least one of the plurality of grain-oriented electrical steel sheets: (1) has a region in which closure domains are formed in a direction crossing a rolling direction and a region in which no closure domains are formed; (2) has an area ratio R.sub.0 of 0.10% to 3.0%, the area ratio R.sub.0 being defined as a ratio of S.sub.0 to S; and (3) has an area ratio R.sub.1a of 50% or more, the area ratio R.sub.1a being defined as a ratio of S.sub.1a to S.sub.1.

Disclosed is a magnetic core having improved reliability. The magnetic core includes 37 to 44 mol % of manganese (Mn), 9 to 16 mol % of zinc (Zn), 42 to 52 mol % of iron (Fe), a magnetic additive, and a non-magnetic additive, wherein the magnetic core has a permeability of 2,900 or more and a core loss of 500 mW/cm.sup.3 or less.

A magnetic core and the like having a stable soft magnetic property, including a plurality of soft magnetic layers which are laminated, wherein a crack is formed in the soft magnetic layers. The soft magnetic layers include Fe as a principal component. The soft magnetic layers include a composition formula (Fe.sub.(1(+))X1.sub.X2.sub.).sub.(1(a+b+c+d+e+f))M.sub.aB.sub.bP.sub.cSi.sub.dC.sub.eS.sub.f, wherein: X1 is one or more selected from the group consisting of Co and Ni, X2 is one or more selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, N, and O and rare-earth elements, M is one or more selected from the group consisting of Nb, Hf, Zr, Ta, Mo, V, and W; and a to f and and are in predetermined ranges. A structure including a nanoheterostructure or an Fe-group nanocrystal is observed in the soft magnetic layers.

A magnetic film includes one or more magnetically conductive layers. Each magnetically conductive layer is cracked to form a plurality of first through-cracks defining a plurality of magnetically conductive segments. The first through-cracks extend along a first direction and form a first regular pattern along an orthogonal second direction at a first pitch P1, such that a Fourier transform of the first regular pattern has a first peak along the second direction at a first spatial frequency corresponding to the first pitch P1. The first through-cracks have an average length L1 along the first direction. L1/P1 is greater than or equal to 5.