A ferromagnetic disk is removably installed in a wellbore. The disk can be installed in the wellbore during oil and gas well completion and production activities to maintain pressure within the wellbore and then can be dislodged. More specifically, a strong magnet is installed within a magnetic tool to dislodge and remove a ferromagnetic disk without breaking the disk. The strong magnet can be a neodymium magnet, electromagnet, or other types of strong magnets.

Provided is a soft magnetic alloy having a composition of a compositional formula (Fe.sub.(1−(α+β))X1.sub.αX2.sub.β).sub.(1−(a+b+c+d+e))P.sub.aC.sub.bSi.sub.cCu.sub.dM.sub.e. X1 is one or more selected from a group consisting of Co and Ni, X2 is one or more selected from a group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Bi, N, 0, and rare earth elements, and M is one or more selected from the group consisting of Nb, Hf, Zr, Ta, Ti, Mo, W and V. 0.050≤a≤0.17, 0<b<0.050, 0.030<c≤0.10, 0<d≤0.020, 0≤e≤0.030, α≥0, β≥0, and 0≤α+β≤0.50.

Provided is a soft magnetic alloy having a composition of a compositional formula (Fe.sub.(1−(α+β))X1.sub.αX2.sub.β).sub.(1−(a+b+c+d+e))P.sub.aC.sub.bSi.sub.cCu.sub.dM.sub.e. X1 is one or more selected from a group consisting of Co and Ni, X2 is one or more selected from a group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Bi, N, 0, and rare earth elements, and M is one or more selected from the group consisting of Nb, Hf, Zr, Ta, Ti, Mo, W and V. 0.050≤a≤0.17, 0<b<0.050, 0.030<c≤0.10, 0<d≤0.020, 0≤e≤0.030, α≥0, β≥0, and 0≤α+β≤0.50.

Methods and systems are provided for dislodging a ferromagnetic disk removably installed in a wellbore. The disk can be installed in the wellbore during oil and gas well completion and production activities to maintain pressure within the wellbore. More specifically, the disclosure relates to using a strong magnet installed within a magnetic tool to dislodge and remove a ferromagnetic disk without breaking the disk. The strong magnet can be a neodymium magnet, electromagnet, or other types of strong magnets.

The magnetic sensor can prevent an increase of a positional detection error of a subject/object even in the case of applying an external magnetic field with a magnetic field intensity exceeding a predetermined range. A magnetic sensor is equipped with a magnetoresistive effect element (MR element) 11 that can detect an external magnetic field and a soft magnetic body shield 12. The soft magnetic body shield(s) 12 are/is positioned above and/or below the MR element 11 in a side view, and the size of the MR element 11 is physically included within a perimeter of the soft magnetic body shield 12.

One object is to provide a method and a device for calculating core loss accurately. A calculation method includes: calculating core loss characteristics of a magnetic part having no superimposed direct current flowing therein, the magnetic part being made of one or more magnetic materials; and calculating a value of core loss of the magnetic part by multiplying the core loss characteristics by a rate of change of the core loss of the magnetic part caused by a superimposed direct current.

An inductor includes a body containing soft magnetic powder and resin, a coil embedded in the body, outer electrodes on the body, and a protective film on the surface of the body. The protective film has a thickness of 10 μm or more and contains silica particles and resin. In the protective film, the silica particles have an average diameter of 15 nm to 75 nm, and the percentage by weight of the silica particles to the resin is between 150% and 250%.

An inductor includes a body containing soft magnetic powder and resin, a coil embedded in the body, outer electrodes on the body, and a protective film on the surface of the body. The protective film has a thickness of 10 μm or more and contains silica particles and resin. In the protective film, the silica particles have an average diameter of 15 nm to 75 nm, and the percentage by weight of the silica particles to the resin is between 150% and 250%.

A wireless power receiving apparatus which wirelessly charges power according to one embodiment of the present invention includes a substrate, a soft magnetic layer which is laminated on the substrate and is formed with a plurality of patterns including at least 3 lines radiated from predetermined points, and a coil which is laminated on the soft magnetic layer and receives electromagnetic energy radiated from a wireless power transmitting apparatus.

A wireless power receiving apparatus which wirelessly charges power according to one embodiment of the present invention includes a substrate, a soft magnetic layer which is laminated on the substrate and is formed with a plurality of patterns including at least 3 lines radiated from predetermined points, and a coil which is laminated on the soft magnetic layer and receives electromagnetic energy radiated from a wireless power transmitting apparatus.