Ta-Nb ALLOY POWDER AND ANODE ELEMENT FOR SOLID ELECTROLYTIC CAPACITOR

A Ta-Nb alloy powder produced by a thermal CVD method, the alloy powder having an Nb content of 1-50 mass%, an average primary-particle diameter of 30-200 nm. The Ta-Nb alloy powder preferably has a CV value per unit mass of the powder (μF·V/g) of 250 kμF·V/g or greater. More preferably, the Ta-Nb alloy powder, when compacted to a density σ (g/cm 3 ) satisfying σ c (g/cm 3 )=-0.012R Nb +3.57 (where R Nb is the Nb content (mass%) in the alloy), has a CV value per unit volume (μF·V/mm 3 ) of 900 μF·V/mm 3 or greater. The Ta-Nb alloy powder gives a capacitor which has a higher capacity than Ta capacitors and in which the oxide coating film has higher thermal stability than in Nb capacitors. Also provided is an anode element for solid electrolytic capacitors which is obtained from the alloy powder.