Abstract: A heat regenerating material particle of an embodiment contains a heat regenerating substance having a maximum value of specific heat at a temperature of 20 K or less is 0.3 J/cm3·K or more, and one metal element selected from the group consisting of calcium (Ca), magnesium (Mg), beryllium (Be), strontium (Sr), aluminum (Al), iron (Fe), copper (Cu), nickel (Ni), and cobalt (Co). The heat regenerating material particle includes a first region and a second region, the second region is closer to an outer edge of the heat regenerating material particle than the first region, and the second region has a higher concentration of the metal element than the first region.

Abstract: A heat regenerating material particle according to an embodiment includes a plurality of heat regenerating substance particles having a maximum volume specific heat value of 0.3 J/cm3·K or more at a temperature of 20 K or lower, and a binder bonding the heat regenerating substance particles, the binder containing water insoluble resin. The heat regenerating material particle has a particle diameter of 500 ?m or less.

Abstract: The flaky magnetic metal particles of the embodiments include a plurality of flaky magnetic metal particles, each of the flaky magnetic metal particles including a first magnetic particle including a flat surface, at least one first element selected from the group consisting of Fe, Co and Ni, an average ratio between the maximum length and the minimum length in the flat surface being between 1 and 5 inclusive, an average thickness of the first magnetic particles being between 10 nm and 100 ?m inclusive, an average aspect ratio of the first magnetic particles being between 5 and 10000 inclusive; and a plurality of second magnetic particles disposed on the flat surface, an average number of the second magnetic particles being five or more, an average diameter of the second magnetic particles being between 10 nm and 1 ?m inclusive.

Abstract: Provided is a method for producing a magnetic material. The method includes preparing magnetic metal particles containing at least one magnetic metal selected from a first group consisting of Fe, Co and Ni, and at least one non-magnetic metal selected from a second group consisting of Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, Ba, Sr, Cr, Mo, Ag, Ga, Sc, V, Y, Nb, Pb, Cu, In, Sn and rare earth elements, pulverizing and reaggregating the magnetic metal particles, and thereby forming composite particles containing a magnetic metal phase and an interstitial phase, and heat-treating the composite particles at a temperature of from 50° C. to 800° C. The particle size distribution of the magnetic metal particles in the preparing magnetic metal particles has two or more peaks.

Abstract: According to an embodiment, a cryogenic regenerator material contains a silver oxide. A molar ratio of silver atoms to oxygen atoms contained in the cryogenic regenerator material: Ag/O is 1.0 or more and 4.0 or less. The cryogenic regenerator material contains at least one selected from AgO, Ag2O and Ag3O as the silver oxide.

Abstract: The soft magnetic material of embodiments includes flattened magnetic metal particles including at least one magnetic metal selected from iron (Fe), cobalt (Co) and nickel (Ni), each of the flattened magnetic metal particles having a thickness of from 10 nm to 100 ?m, an aspect ratio of from 5 to 10,000, and a lattice strain of from 0.01% to 10%, and being oriented with magnetic anisotropy in one direction within aligned flattened surface; and an interposed phase existing between the flattened magnetic metal particles and including at least one of oxygen (O), carbon (C), nitrogen (N) and fluorine (F).

Abstract: The flaky magnetic metal particles of the embodiments include a plurality of flaky magnetic metal particles, each of the flaky magnetic metal particles including a first magnetic particle including a flat surface, at least one first element selected from the group consisting of Fe, Co and Ni, an average ratio between the maximum length and the minimum length in the flat surface being between 1 and 5 inclusive, an average thickness of the first magnetic particles being between 10 nm and 100 ?m inclusive, an average aspect ratio of the first magnetic particles being between 5 and 10000 inclusive; and a plurality of second magnetic particles disposed on the flat surface, an average number of the second magnetic particles being five or more, an average diameter of the second magnetic particles being between 10 nm and 1 ?m inclusive.

Abstract: Provided is a magnetic material including a plurality of flat particles containing a magnetic metal, and a matrix phase disposed around the flat particles and having higher electrical resistance than the flat particles. In a cross-section of the magnetic material, the aspect ratio of the flat particles is 10 or higher. If the major axis of one of the flat particles is designated as L and the length of a straight line connecting two endpoints of the flat particle is designated as W, the proportion of the area surrounded by the outer peripheries of parts in which flat particles satisfying the relationship: W ?0.95×L are continuously laminated, is 10% or more of the cross-section.

Abstract: According to an embodiment, a cryogenic regenerator material contains a silver oxide. A molar ratio of silver atoms to oxygen atoms contained in the cryogenic regenerator material: Ag/O is 1.0 or more and 4.0 or less. The cryogenic regenerator material contains at least one selected from AgO, Ag2O and Ag3O as the silver oxide.

Abstract: The flaky magnetic metal particles of the embodiments include a plurality of flaky magnetic metal particles, each of the flaky magnetic metal particles including a first magnetic particle including a flat surface, at least one first element selected from the group consisting of Fe, Co and Ni, an average ratio between the maximum length and the minimum length in the flat surface being between 1 and 5 inclusive, an average thickness of the first magnetic particles being between 10 nm and 100 ?m inclusive, an average aspect ratio of the first magnetic particles being between 5 and 10000 inclusive; and a plurality of second magnetic particles disposed on the flat surface, an average number of the second magnetic particles being five or more, an average diameter of the second magnetic particles being between 10 nm and 1 ?m inclusive.

Abstract: The soft magnetic material of embodiments includes flattened magnetic metal particles including at least one magnetic metal selected from iron (Fe), cobalt (Co) and nickel (Ni), each of the flattened magnetic metal particles having a thickness of from 10 nm to 100 ?m, an aspect ratio of from 5 to 10,000, and a lattice strain of from 0.01% to 10%, and being oriented with magnetic anisotropy in one direction within aligned flattened surface; and an interposed phase existing between the flattened magnetic metal particles and including at least one of oxygen (O), carbon (C), nitrogen (N) and fluorine (F).

Abstract: A magnetic metal particle aggregate includes a plurality of magnetic metal particles including at least one magnetic metal selected from a first group consisting of Fe, Co, and Ni. The plurality of magnetic metal particles are partly bound with each other, and an average particle diameter of the plurality of magnetic metal particles is 10 nm or more and 50 nm or less. The magnetic metal particle aggregate has an average particle diameter of 15 nm or more and 200 nm or less.

Abstract: A magnetic material is disclosed, which includes magnetic particles containing at least one magnetic metal selected from the group including Fe, Co and Ni, and at least one non-magnetic metal selected from Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, rare earth elements, Ba and Sr; a first coating layer of a first oxide that covers at least a portion of the magnetic particles; oxide particles of a second oxide that is present between the magnetic particles and constitutes an eutectic reaction system with the first oxide; and an oxide phase that is present between the magnetic particles and has an eutectic structure of the first oxide and the second oxide.

Abstract: A radio wave absorber according to an embodiment includes a plurality of metal particles including at least one kind of magnetic metal element selected from a first group of Fe, Co, and Ni. Each of the plurality of metal particles has a linear expansion coefficient of 1×10?6/K or more and 10×10?6/K or less. The radio wave absorber also includes a binding layer binding the metal particles and having higher resistance than the metal particle, wherein a volume filling ratio of the metal particles in the radio wave absorber is 10% or more and 50% or less.

Abstract: Provided is a magnetic material which includes a plurality of magnetic metal particles having a rate of change in the lattice constant of ±1% or less with respect to the lattice constant obtained after a heat treatment at 1000° C., a plurality of insulating coating layers insulating and covering at least a portion of the magnetic metal particles, and an insulating resin disposed around the magnetic metal particles and the insulating coating layers. The insulating coating layers are in contact with one another.

Abstract: Provided is a method for producing a magnetic material, the method including preparing a mixed phase material including a first magnetic metal phase formed from a magnetic metal and a second phase containing any one of oxygen (O), nitrogen (N) or carbon (C) and a non-magnetic metal, conducting a first heat treatment to the mixed phase material at a temperature of from 50° C. to 800° C., forming nanoparticle aggregates including a plurality of magnetic metal nanoparticles formed from the first magnetic metal phase and the second phase, and conducting a second heat treatment to the nanoparticle aggregates at a temperature of from 50° C. to 800° C. The nanoparticle aggregates are formed by decreasing an average particle size and a particle size distribution variation of the first magnetic metal phase after the first heat treatment.

Abstract: Provided is a method for producing a magnetic material. The method includes preparing magnetic metal particles containing at least one magnetic metal selected from a first group consisting of Fe, Co and Ni, and at least one non-magnetic metal selected from a second group consisting of Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, Ba, Sr, Cr, Mo, Ag, Ga, Sc, V, Y, Nb, Pb, Cu, In, Sn and rare earth elements, pulverizing and reaggregating the magnetic metal particles, and thereby forming composite particles containing a magnetic metal phase and an interstitial phase, and heat-treating the composite particles at a temperature of from 50° C. to 800° C. The particle size distribution of the magnetic metal particles in the preparing magnetic metal particles has two or more peaks.

Abstract: Provided is a magnetic material including a plurality of flat particles containing a magnetic metal, and a matrix phase disposed around the flat particles and having higher electrical resistance than the flat particles. In a cross-section of the magnetic material, the aspect ratio of the flat particles is 10 or higher. If the major axis of one of the flat particles is designated as L and the length of a straight line connecting two endpoints of the flat particle is designated as W, the proportion of the area surrounded by the outer peripheries of parts in which flat particles satisfying the relationship: W?0.95×L are continuously laminated, is 10% or more of the cross-section.

Abstract: A radio wave absorber according to an embodiment includes a plurality of metal particles including at least one kind of magnetic metal element selected from a first group of Fe, Co, and Ni. Each of the plurality of metal particles has a linear expansion coefficient of 1×10?6/K or more and 10×10?6/K or less. The radio wave absorber also includes a binding layer binding the metal particles and having higher resistance than the metal particle, wherein a volume filling ratio of the metal particles in the radio wave absorber is 10% or more and 50% or less.

Abstract: An antenna device arranged around a printed circuit board is provided. The antenna device has an antenna element connected to a feeder circuit provided on the printed board. The antenna device has an isolating material provided between the antenna element and the substrate material. The isolating material is constituted by an insulating substrate material and a plurality of pieces of magnetic material provided on the substrate material. Adjacent ones of the pieces of the magnetic material are arranged separate from each other.