Aspects of the present disclosure include systems, structures, circuits, and methods providing planar transformers and planar transformer structures. The planar transformers and transformer structures can include first and second core layers of soft ferromagnetic material on opposite sides of an electrical substrate. First and second coils can be configured as conductive traces disposed on the opposite sides of the substrate. The first and second soft ferromagnetic layers are in contact in a contact region. One or more holes are disposed in either or both of the soft ferromagnetic layers and contain soft ferromagnetic material to reduce reluctance of the transformer structure. The planar transformer can be included in integrated circuit (chip) packages or modules. The packages and modules may include various types of circuits; in some examples, chip packages or modules may include a gate driver or other high voltage circuit.

Aspects of the present disclosure include systems, structures, circuits, and methods providing planar transformers and planar transformer structures. The planar transformers and transformer structures can include first and second core layers of soft ferromagnetic material on opposite sides of an electrical substrate. First and second coils can be configured as conductive traces disposed on the opposite sides of the substrate. The first and second soft ferromagnetic layers are in contact in a contact region. One or more holes are disposed in either or both of the soft ferromagnetic layers and contain soft ferromagnetic material to reduce reluctance of the transformer structure. The planar transformer can be included in integrated circuit (chip) packages or modules. The packages and modules may include various types of circuits; in some examples, chip packages or modules may include a gate driver or other high voltage circuit.

Present disclosure relates to magnetic materials, chips having magnetic materials, and methods of forming magnetic materials. In certain embodiments, magnetic materials may include a seed layer, and a cobalt-based alloy formed on seed layer. The seed layer may include copper, cobalt, nickel, platinum, palladium, ruthenium, iron, nickel alloy, cobalt-iron-boron alloy, nickel-iron alloy, and any combination of these materials. In certain embodiments, the chip may include one or more on-chip magnetic structures. Each on-chip magnetic structure may include a seed layer, and a cobalt-based alloy formed on seed layer. In certain embodiments, method may include: placing a seed layer in an aqueous electroless plating bath to form a cobalt-based alloy on seed layer. In certain embodiments, the aqueous electroless plating bath may include sodium tetraborate, an alkali metal tartrate, ammonium sulfate, cobalt sulfate, ferric ammonium sulfate and sodium borohydride and has a pH between about 9 to about 13.

Core-shell-core nanoparticles of an iron-cobalt alloy core, a silica shell and a manganese bismuth alloy core or nanoparticle on the surface of the silica shell (FeCo/SiO.sub.2/MnBi) are provided. The core-shell-core nanoparticles are alternative materials to rare-earth permanent magnets because of the hard magnetic manganese bismuth in nanometer proximity to the soft magnetic iron cobalt.

The present invention provides a method for improving coercive force of magnets, this method comprises steps as follows: S2) coating step: coating a coating material on the surface of a magnet and drying it; and S3) infiltrating step: heat treating the magnet obtained from the coating step S2). The coating material comprises (1) metal calcium particles and (2) particles of a material containing a rare earth element; the rare earth element is at least one selected from Praseodymium, Neodymium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium and Lutetium. The method of the present invention can significantly increase coercive force of a permanent magnet material, while remanence and magnetic energy product hardly decrease. In addition, the method of the present invention can significantly decrease the amount of a rare earth element, and accordingly, decrease the production cost.

The present invention provides a method for improving coercive force of magnets, this method comprises steps as follows: S2) coating step: coating a coating material on the surface of a magnet and drying it; and S3) infiltrating step: heat treating the magnet obtained from the coating step S2). The coating material comprises (1) metal calcium particles and (2) particles of a material containing a rare earth element; the rare earth element is at least one selected from Praseodymium, Neodymium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium and Lutetium. The method of the present invention can significantly increase coercive force of a permanent magnet material, while remanence and magnetic energy product hardly decrease. In addition, the method of the present invention can significantly decrease the amount of a rare earth element, and accordingly, decrease the production cost.

Some variations provide a magnetically anisotropic structure comprising a hexaferrite film disposed on a substrate, wherein the hexaferrite film contains a plurality of discrete and aligned magnetic hexaferrite particles, wherein the hexaferrite film is characterized by an average film thickness from about 1 micron to about 500 microns, and wherein the hexaferrite film contains less than 2 wt % organic matter. The hexaferrite film does not require a binder. Discrete particles are not sintered or annealed together because the maximum processing temperature to fabricate the structure is 500 C. or less, such as 250 C. or less. The magnetic hexaferrite particles may contain barium hexaferrite (BaFe.sub.12O.sub.19) and/or strontium hexaferrite (SrFe.sub.12O.sub.19). The hexaferrite film may be characterized by a remanence-to-saturation magnetization ratio of at least 0.7. Methods of making and using the magnetically anisotropic structure are also described.

Some variations provide a magnetically anisotropic structure comprising a hexaferrite film disposed on a substrate, wherein the hexaferrite film contains a plurality of discrete and aligned magnetic hexaferrite particles, wherein the hexaferrite film is characterized by an average film thickness from about 1 micron to about 500 microns, and wherein the hexaferrite film contains less than 2 wt % organic matter. The hexaferrite film does not require a binder. Discrete particles are not sintered or annealed together because the maximum processing temperature to fabricate the structure is 500 C. or less, such as 250 C. or less. The magnetic hexaferrite particles may contain barium hexaferrite (BaFe.sub.12O.sub.19) and/or strontium hexaferrite (SrFe.sub.12O.sub.19). The hexaferrite film may be characterized by a remanence-to-saturation magnetization ratio of at least 0.7. Methods of making and using the magnetically anisotropic structure are also described.

A micro fabricated electromagnetic device and method for fabricating its component structures, the device having a layered magnetic core of a potentially unlimited number of alternating insulating and magnetic layers depending upon application, physical property and performance characteristic requirements for the device. Methods for fabricating the high performing device permit cost effective, high production rates of the device and its component structures without any degradation in device performance resulting from component layering.

An electromagnetic material for an inductance for operation at cryogenic temperatures including, in an electrically insulating matrix, metal nanoparticles with superparamagnetic behavior of size less than or equal to 30 nm and having a magnetic permeability greater than or equal to 1.5 for a frequency between 5 GHz and 50 GHz.