Powdered niobium, sintered body thereof, capacitor using the sintered body and production method of the capacitor

Abstract

The present invention relates to a powdered niobium for a capacitor, characterized in that the content of each of the elements such as iron, nickel, cobalt, silicon, sodium, potassium and magnesium is about 100 ppm by weight or less or that the total content thereof is about 350 ppm by weight or less is used, a sintered body thereof, a sintered body comprising niobium monoxide crystal and/or diniobium mononitride crystal, a capacitor using the sintered body and the production method of the capacitor. A capacitor using the above described niobium sintered body has a large capacity per the unit weight, a good specific leakage current value and excellent high temperature property.

1 - 14 . (canceled)  
     
     
         15 . A producing method of the powdered niobium for a capacitor comprising at least one of niobium nitride, niobium carbide and niobium boride of 50 ppm by weight to 200,000 ppm by weight and at least one element selected from the group consisting of iron, nickel, cobalt, silicon, sodium, potassium and magnesium in an amount of 100 ppm by weight or less, comprising washing the powdered niobium by using an acid containing at least one acid of a hydrofluoric acid, a nitric acid, a sulfuric acid and a hydrochloric acid and an alkali, or by using the acid, an alkali and a hydrogen peroxide in sequence or in combination.  
     
     
         16 . A producing method of the powdered niobium for a capacitor comprising at least one of niobium nitride, niobium carbide and niobium boride of 50 ppm by weight to 200,000 ppm by weight and at least one element selected from the group consisting of iron, nickel, cobalt, silicon, sodium, potassium and magnesium in a total amount of 350 ppm by weight or less, comprising washing the powdered niobium by using an acid containing at least one acid of a hydrofluoric acid, a nitric acid, a sulfuric acid and a hydrochloric acid and an alkali, or by using the acid, an alkali and a hydrogen peroxide in sequence or in combination.  
     
     
         17 . A producing method of the powdered niobium for a capacitor comprising at least one of niobium nitride, niobium carbide and niobium boride of 50 ppm by weight to 200,000 ppm by weight and at least one element selected from the group consisting of iron, nickel, cobalt, silicon, sodium, potassium and magnesium in an amount of 100 ppm by weight or less and in a total amount of 350 ppm by weight or less, comprising washing the powdered niobium by using an acid containing at least one acid of a hydrofluoric acid, a nitric acid, a sulfuric acid and a hydrochloric acid and an alkali, or by using the acid, an alkali and a hydrogen peroxide in sequence or in combination.