There is a problem that when a silver powder sintering paste that is substantially free from resin is used, an organic solvent used as a dispersion medium bleeds, which results in contamination and wire bonding defects. In order to solve the problem, provided is a metal powder sintering paste that contains, as a principal component, silver particles having an average particle diameter (a median diameter) of 0.3 μm to 5 μm and further contains an anionic surfactant but is substantially free from resin.

There is a problem that when a silver powder sintering paste that is substantially free from resin is used, an organic solvent used as a dispersion medium bleeds, which results in contamination and wire bonding defects. In order to solve the problem, provided is a metal powder sintering paste that contains, as a principal component, silver particles having an average particle diameter (a median diameter) of 0.3 μm to 5 μm and further contains an anionic surfactant but is substantially free from resin.

Flaky magnetic metal particles of embodiments each have a flat surface and a magnetic metal phase containing iron (Fe), cobalt (Co), and silicon (Si). An amount of Co is from 0.001 at % to 80 at % with respect to the total amount of Fe and Co. An amount of Si is from 0.001 at % to 30 at % with respect to the total amount of the magnetic metal phase. The flaky magnetic metal particles have an average thickness of from 10 nm to 100 μm. An average value of the ratio of the average length in the flat surface with respect to a thickness in each of the flaky magnetic metal particles is from 5 to 10,000. The flaky magnetic metal particles have the difference in coercivity on the basis of direction within the flat surface.

Flaky magnetic metal particles of embodiments each have a flat surface and a magnetic metal phase containing iron (Fe), cobalt (Co), and silicon (Si). An amount of Co is from 0.001 at % to 80 at % with respect to the total amount of Fe and Co. An amount of Si is from 0.001 at % to 30 at % with respect to the total amount of the magnetic metal phase. The flaky magnetic metal particles have an average thickness of from 10 nm to 100 μm. An average value of the ratio of the average length in the flat surface with respect to a thickness in each of the flaky magnetic metal particles is from 5 to 10,000. The flaky magnetic metal particles have the difference in coercivity on the basis of direction within the flat surface.

Provided are gold-coated flat silver particles, a dispersion including the gold-coated flat silver particles and a dispersion medium, a method of the dispersion, a coating film including the gold-coated flat silver particles, and an antireflection optical member. The gold-coated flat silver particles include flat silver particles and a gold coating layer, in which an average thickness of the gold coating layer on principal planes of the particles is 0.1 nm to 2 nm, and a ratio of the average thickness of the gold coating layer on the principal planes of the particles to an average thickness of the gold coating layer on edge surfaces of the particles is 0.02 or higher.

Provided are gold-coated flat silver particles, a dispersion including the gold-coated flat silver particles and a dispersion medium, a method of the dispersion, a coating film including the gold-coated flat silver particles, and an antireflection optical member. The gold-coated flat silver particles include flat silver particles and a gold coating layer, in which an average thickness of the gold coating layer on principal planes of the particles is 0.1 nm to 2 nm, and a ratio of the average thickness of the gold coating layer on the principal planes of the particles to an average thickness of the gold coating layer on edge surfaces of the particles is 0.02 or higher.

The present invention provides a contact member that strikes a balance between low electrical resistance and sliding durability under the condition of load as low as about 0.1 N. A contact member of the invention has a metal base and a coating disposed on at least part of the metal base. The coating contains fluorinated oil having a polar group, and metal particles surface-treated with a fluorine-based compound having a polar group.

A copper paste for joining contains metal particles and a dispersion medium, in which the copper paste for joining contains copper particles as the metal particles, and the copper paste for joining contains dihydroterpineol as the dispersion medium. A method for manufacturing a joined body is a method for manufacturing a joined body which includes a first member, a second member, and a joining portion that joins the first member and the second member, the method including: a first step of printing the above-described copper paste for joining to at least one joining surface of the first member and the second member to prepare a laminate having a laminate structure in which the first member, the copper paste for joining, and the second member are laminated in this order; and a second step of sintering the copper paste for joining of the laminate.

The present disclosure discloses an yttrium (Y)-added rare-earth permanent magnetic material and a preparation method thereof. A chemical formula of the material expressed in atomic percentage is (YxRE1-x)aFebalMbNc, wherein 0.05≤x≤0.4, 7≤a≤13, 0≤b≤3, 5≤c≤20, and the balance is Fe, namely, bal=100-a-b-c; RE represents a rare-earth element Sm, or a combination of the rare-earth element Sm and any one or more elements of Zr, Nd and Pr; M represents Co and/or Nb; and N represents nitrogen. In the preparation method, the rare-earth element Y is utilized to replace the element Sm of a samarium-iron-nitrogen material. By regulating a ratio of the element Sm to the element Y, viscosity of an alloy liquid can be reduced, and an amorphous forming ability of the material is enhanced.

The present disclosure discloses an yttrium (Y)-added rare-earth permanent magnetic material and a preparation method thereof. A chemical formula of the material expressed in atomic percentage is (YxRE1-x)aFebalMbNc, wherein 0.05≤x≤0.4, 7≤a≤13, 0≤b≤3, 5≤c≤20, and the balance is Fe, namely, bal=100-a-b-c; RE represents a rare-earth element Sm, or a combination of the rare-earth element Sm and any one or more elements of Zr, Nd and Pr; M represents Co and/or Nb; and N represents nitrogen. In the preparation method, the rare-earth element Y is utilized to replace the element Sm of a samarium-iron-nitrogen material. By regulating a ratio of the element Sm to the element Y, viscosity of an alloy liquid can be reduced, and an amorphous forming ability of the material is enhanced.