Abstract: An object of the present invention is to provide nitrogen-containing metallic powder at high productivity, which powder contains a metal such as niobium or tantalum containing nitrogen uniformly, and enables production of an anode electrode that has high specific capacitance and low leakage current and that exhibits excellent reliability for a prolonged period of time. There is provided nitrogen-containing metallic powder which is a solid solution containing 50-20,000 ppm nitrogen, in which the metal that constitutes the metallic powder is niobium or tantalum. The nitrogen-containing metallic powder is produced through the process in which while a metallic compound is reduced with a reducing agent, a nitrogen-containing gas is introduced into a reaction system to thereby form metal, and nitrogen is simultaneously incorporated into metal.

Abstract: The present invention provides an electrolytic capacitor that operates stably even when used for a long period of time under severe conditions, and forms an intermediate composition portion of metal and oxide within a chemical conversion film to a thickness of 40 nm or more so as to suppress the migration of oxygen atoms within a chemical conversion film of a valve metal. This intermediate composition portion is obtained by subjecting a base metal comprised by containing nitrogen in a valve action metal to anodic oxidation treatment.

Abstract: A niobium or tantalum powder of the present invention comprises aggregates in which primary particles of niobium or tantalum are aggregated, and have a pore distribution having a peak in the range from 1 to 20 ?m as measured by mercury porosimetry. That is, the niobium or tantalum powder of the present invention comprises aggregates having large pores, which connect with vacancies between the primary particles and facilitate the permeation of an electrolyte over the entirety of the inside of each aggregate. Accordingly, a solid electrolytic capacitor comprising an anode electrode made of the niobium or tantalum powder has high capacity and also a low ESR.

Abstract: An object of the present invention is to provide nitrogen-containing metallic powder at high productivity, which powder contains a metal such as niobium or tantalum containing nitrogen uniformly, and enables production of an anode electrode that has high specific capacitance and low leakage current and that exhibits excellent reliability for a prolonged period of time. There is provided nitrogen-containing metallic powder which is a solid solution containing 50–20,000 ppm nitrogen, in which the metal that constitutes the metallic powder is niobium or tantalum. The nitrogen-containing metallic powder is produced through the process in which while a metallic compound is reduced with a reducing agent, a nitrogen-containing gas is introduced into a reaction system to thereby form metal, and nitrogen is simultaneously incorporated into metal.

Abstract: A nitrogen containing metal powder wicth a large specific surface area, and containing a suitable quantity of nitrogen dispersed uniformly within the metal is produced with good productivity, and provides a solid electrolytic capacitor with a high capacitance, minimal leakage current, and excellent long term reliability. This nitrogen containing metal powder has a ratio W/S between the nitrogen content W [ppm] of the powder, and the specific surface area S [m2/g], as measured by a BET method, that falls within a range from 500 to 3000. This type of powder can be produced by a process in which a metal salt containing the metal is reacted with a reducing agent and undergoes reduction within a diluent salt, thereby generating the metal, wherein a nitrogen containing gas is introduced into the space contacting the reaction melt comprising the metal salt, the reducing agent and the diluent salt, thereby generating the metal and incorporating the nitrogen within the metal.

Abstract: 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 including aggregated columnar particles. A tantalum or niobium powder contains radially aggregated particles formed by a plurality of columnar particles aggregated radially.

Abstract: The tantalum powder for capacitors of the present invention has a specific surface area SB as determined by the BET method of 1.3 m2/g or more, and an SB/SF ratio between the specific surface area SB as determined by the BET method and the specific surface area SF determined by the FSS method of 4 to 10. This tantalum powder not only has a large specific surface area SB, but also has suitable cohesive strength and uniform porosity. Consequently, a solid state electrolytic capacitor having high capacitance and low ESR can be obtained by providing with a capacitor anode formed from a sintered body of this tantalum powder. In addition, whether or not this tantalum powder is suitable for the production of a tantalum capacitor having high capacitance and low ESR can be determined easily and reliably by evaluating the tantalum powder using the specific surface area SB as determined by the BET method and the SB/SF ratio between SB and the specific surface area SF determined by the FSS method.

Abstract: 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.

Abstract: The present invention allows the obtaining of a condenser having high electrostatic capacitance by optimizing the anodic oxidation treatment voltage and particle size of the metal powder for the condenser during production of an electrolytic condenser anode body, and forming an anodic oxide film of a thickness that is suitable for the particle size of the metal powder. In the present invention, and electrolytic condenser anode body is produced by using the metal powder containing 50 wt % or more of particles, in which the primary particle diameter as determined by image analysis is within the range of 2.7×Vf to 10×Vf (units: nm), when the anodic oxidation treatment voltage during formation of an anodic oxide film on an anode sintered body composed of the metal powder is Vf (units: V).

Abstract: An object of the present invention is to provide nitrogen-containing metallic powder at high productivity, which powder contains a metal such as niobium or tantalum containing nitrogen uniformly, and enables production of an anode electrode that has high specific capacitance and low leakage current and that exhibits excellent reliability for a prolonged period of time. There is provided nitrogen-containing metallic powder which is a solid solution containing 50-20,000 ppm nitrogen, in which the metal that constitutes the metallic powder is niobium or tantalum. The nitrogen-containing metallic powder is produced through the process in which while a metallic compound is reduced with a reducing agent, a nitrogen-containing gas is introduced into a reaction system to thereby form metal, and nitrogen is simultaneously incorporated into metal.

Abstract: An object of the present invention is to provide nitrogen-containing metallic powder at high productivity, which powder contains a metal such as niobium or tantalum containing nitrogen uniformly, and enables production of an anode electrode that has high specific capacitance and low leakage current and that exhibits excellent reliability for a prolonged period of time. There is provided nitrogen-containing metallic powder which is a solid solution containing 50-20,000 ppm nitrogen, in which the metal that constitutes the metallic powder is niobium or tantalum. The nitrogen-containing metallic powder is produced through the process in which while a metallic compound is reduced with a reducing agent, a nitrogen-containing gas is introduced into a reaction system to thereby form metal, and nitrogen is simultaneously incorporated into metal.

Abstract: The tantalum powder for capacitors of the present invention has a specific surface area SB as determined by the BET method of 1.3 m2/g or more, and an SB/SF ratio between the specific surface area SB as determined by the BET method and the specific surface area SF determined by the FSS method of 4 to 10. This tantalum powder not only has a large specific surface area SB, but also has suitable cohesive strength and uniform porosity.

Abstract: The dielectric characteristic and resistance against the dielectric characteristic deterioration of tantalum powder for use in a solid electrolyte capacitor are improved by incorporating phosphorus and boron dopant sources into tantalum material at the reducing step of K.sub.2 TaF.sub.7 or by incorporating one of the two dopant sources at the reducing step and the other dopant source at the heat-treating step.