Abstract: A thin film for a reflection film or a semi-transparent reflection film, which has a compound phase comprising at least one selected from the group consisting of a nitride, an oxide, a complex oxide, a nitroxide, a carbide, a sulfide, a chloride, a silicide, a fluoride, a boride, a hydride, a phosphide, a selenide and a telluride of gallium, palladium or copper, dispersed in a matrix formed of silver or a silver alloy. The compound phase in the thin film may include at least one compound selected from the group consisting of nitride, oxide, complex oxide, nitroxide, carbide, sulfide, chloride, silicide, fluoride, boride, hydride, phosphide, selenide and telluride of silver. The thin film of the present invention minimizes the deterioration of the reflectance even after a long period of use, and can prolong the life of various devices which use the thin film as a reflection film, such as an optical recording medium and a display.

Abstract: A method for recovering platinum group elements comprises charging into a closed electric furnace and melting, together with flux components and a reducing agent, a platinum group element-containing substance to be processed and a copper source material containing copper oxide, sinking molten metal of primarily metallic copper below a molten slag layer of primarily oxides, and enriching the platinum group elements in the molten metal sunk below, and is characterized in that molten slag whose copper content has decreased to 3.0 wt % or less is discharged from the electric furnace and that the copper source material charged into the electric furnace is a granular copper source material of a grain diameter of not less than 0.1 mm and not greater than 10 mm.

Abstract: A process of hexaamminerhodium trihydroxide, hexaammineplatinum (IV) tetrahydroxide, tetraammineplatinum (II) dihydroxide and tetraamminepalladium dihydroxide. Hexaamminerhodium trihydroxide is prepared by forming a solution of hexaamminerhodium (III) chloride by reacting a solution of rhodium (III) chloride and an excess amount of aqueous ammonia, heating the thus formed solution to impart thereto a pH of 7.5 to 8.0, and contacting the hexaamminerhodium (III) chloride solution with an anion exchange resin having an OH form. Hexaammineplatinum (IV) tetrahydroxide is prepared by dissolving ammonium chloroplatinate into aqueous ammonia, and contacting the resulting solution of hexaammineplatinum (IV) tetrachloride with an anion exchange resin having an OH form. Tetraammineplatinum (II) dihydroxide is prepared by contacting a solution of tetraammineplatinum (II) dichloride with an anion exchange resin having an OH form.