Powdered tantalum, niobium, production process thereof and porous sintered body and solid electrolytic capacitor using the powdered tantalum or niobium

摘要

A tantalum or niobium powder that can provide a porous sintered tantalum or niobium body having a large surface area and involving a lower risk of failure to form a solid electrolyte film, where a material serving as a tantalum or niobium ion source is dissolved in a molten salt, upon which a reducing agent is allowed to act, resulting in reduction to the metal state of the tantalum or niobium ions dissolved in the molten salt, to thereby obtain a tantalum or niobium powder comprising aggregated columnar particles. A tantalum or niobium powder contains radially aggregated particles formed by a plurality of columnar particles aggregated radially.