NIOBIUM POWDER, SINTERED COMPACT THEREOF, CHEMICALLY MODIFIED PRODUCT THEREOF AND CAPACITOR USING THEM

摘要

A niobium powder containing nitrogen for a capacitor, characterized in that the layer of a particle therein having a depth from the surface of 50 to 200 nm has an average nitrogen concentration of 0.29 to 4 mass %, and preferably also in that the layer of a particle therein having a depth from the surface up to 50 nm has an average nitrogen concentration of 0.19 to 1 mass %; a sintered compact of the niobium powder; a chemically modified product of the sintered compact; and a capacitor using them. The niobium powder can be used for providing a capacitor exhibiting a reduced leakage current.